EP3623748B1 - System for determining a longitudinal elongation of a belt - Google Patents

System for determining a longitudinal elongation of a belt Download PDF

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Publication number
EP3623748B1
EP3623748B1 EP19190163.6A EP19190163A EP3623748B1 EP 3623748 B1 EP3623748 B1 EP 3623748B1 EP 19190163 A EP19190163 A EP 19190163A EP 3623748 B1 EP3623748 B1 EP 3623748B1
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EP
European Patent Office
Prior art keywords
belt
marking part
transmitter
marking
alternating field
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
EP19190163.6A
Other languages
German (de)
French (fr)
Other versions
EP3623748A1 (en
Inventor
Heiko Sattler
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
ContiTech Antriebssysteme GmbH
Original Assignee
ContiTech Antriebssysteme GmbH
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Publication date
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Publication of EP3623748A1 publication Critical patent/EP3623748A1/en
Application granted granted Critical
Publication of EP3623748B1 publication Critical patent/EP3623748B1/en
Active legal-status Critical Current
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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
    • G01B7/16—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring the deformation in a solid, e.g. by resistance strain gauge
    • G01B7/24—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring the deformation in a solid, e.g. by resistance strain gauge using change in magnetic properties
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
    • B65G43/00—Control devices, e.g. for safety, warning or fault-correcting
    • B65G43/02—Control devices, e.g. for safety, warning or fault-correcting detecting dangerous physical condition of load carriers, e.g. for interrupting the drive in the event of overheating
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16G—BELTS, CABLES, OR ROPES, PREDOMINANTLY USED FOR DRIVING PURPOSES; CHAINS; FITTINGS PREDOMINANTLY USED THEREFOR
    • F16G5/00—V-belts, i.e. belts of tapered cross-section
    • F16G5/04—V-belts, i.e. belts of tapered cross-section made of rubber
    • F16G5/06—V-belts, i.e. belts of tapered cross-section made of rubber with reinforcement bonded by the rubber
    • F16G5/08—V-belts, i.e. belts of tapered cross-section made of rubber with reinforcement bonded by the rubber with textile reinforcement
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16G—BELTS, CABLES, OR ROPES, PREDOMINANTLY USED FOR DRIVING PURPOSES; CHAINS; FITTINGS PREDOMINANTLY USED THEREFOR
    • F16G5/00—V-belts, i.e. belts of tapered cross-section
    • F16G5/04—V-belts, i.e. belts of tapered cross-section made of rubber
    • F16G5/06—V-belts, i.e. belts of tapered cross-section made of rubber with reinforcement bonded by the rubber
    • F16G5/10—V-belts, i.e. belts of tapered cross-section made of rubber with reinforcement bonded by the rubber with metal reinforcement
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16G—BELTS, CABLES, OR ROPES, PREDOMINANTLY USED FOR DRIVING PURPOSES; CHAINS; FITTINGS PREDOMINANTLY USED THEREFOR
    • F16G5/00—V-belts, i.e. belts of tapered cross-section
    • F16G5/12—V-belts, i.e. belts of tapered cross-section made of plastics
    • F16G5/14—V-belts, i.e. belts of tapered cross-section made of plastics with reinforcement bonded by the plastic material
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L1/00—Measuring force or stress, in general
    • G01L1/12—Measuring force or stress, in general by measuring variations in the magnetic properties of materials resulting from the application of stress
    • G01L1/122—Measuring force or stress, in general by measuring variations in the magnetic properties of materials resulting from the application of stress by using permanent magnets
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M13/00—Testing of machine parts
    • G01M13/02—Gearings; Transmission mechanisms
    • G01M13/023—Power-transmitting endless elements, e.g. belts or chains
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M5/00—Investigating the elasticity of structures, e.g. deflection of bridges or air-craft wings
    • G01M5/0041—Investigating the elasticity of structures, e.g. deflection of bridges or air-craft wings by determining deflection or stress
    • G01M5/005—Investigating the elasticity of structures, e.g. deflection of bridges or air-craft wings by determining deflection or stress by means of external apparatus, e.g. test benches or portable test systems
    • G01M5/0058—Investigating the elasticity of structures, e.g. deflection of bridges or air-craft wings by determining deflection or stress by means of external apparatus, e.g. test benches or portable test systems of elongated objects, e.g. pipes, masts, towers or railways
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
    • B65G15/00—Conveyors having endless load-conveying surfaces, i.e. belts and like continuous members, to which tractive effort is transmitted by means other than endless driving elements of similar configuration
    • B65G15/30—Belts or like endless load-carriers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
    • B65G2203/00—Indexing code relating to control or detection of the articles or the load carriers during conveying
    • B65G2203/02—Control or detection
    • B65G2203/0266—Control or detection relating to the load carrier(s)
    • B65G2203/0275—Damage on the load carrier
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
    • B65G2203/00—Indexing code relating to control or detection of the articles or the load carriers during conveying
    • B65G2203/04—Detection means
    • B65G2203/042—Sensors
    • B65G2203/043—Magnetic
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
    • G01B7/02—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring length, width or thickness
    • G01B7/04—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring length, width or thickness specially adapted for measuring length or width of objects while moving
    • G01B7/042—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring length, width or thickness specially adapted for measuring length or width of objects while moving for measuring length
    • G01B7/046—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring length, width or thickness specially adapted for measuring length or width of objects while moving for measuring length using magnetic means

Definitions

  • the invention relates to a system for determining the longitudinal elongation of a belt.
  • a system that has a belt and a drive device for the belt is basically known from the prior art.
  • the drive device has several, for example two, pulleys.
  • the belt is designed to run annularly in a circumferential direction and at least partially wraps around the pulleys.
  • the belt can be driven in the circumferential direction by the drive device.
  • a belt is preferably a drive belt for transmitting tensile forces.
  • a belt is often exposed to pretension, useful forces, centrifugal forces and/or bends.
  • the service life of a belt is at least partly determined by the stretch of the belt, in particular the stretch in the circumferential direction.
  • the rate of rotation at which the belt moves and/or the power required to drive the belt can indicate the load on the belt.
  • this load can only be used to give a rough estimate of the actual local stretching of the belt. An exact determination based on the aforementioned load is not possible.
  • Strain gauges are known from the prior art. However, the use of a strain gauge requires an electrical measuring circuit that is to be coupled to the strain gauge in order to evaluate a strain detected by the strain gauge or to provide a corresponding evaluation signal. In order to use a strain gauge for a belt, you also need one Attachment of the aforementioned evaluation circuit to the belt. In particular, if the belt is exposed to a high temperature during use, which is influenced, for example, by friction of the belt on a deflection pulley and/or by a high ambient temperature, a robust evaluation circuit can only be produced with very high technical effort and corresponding costs High temperatures ensure reliable measurement of the strain using the strain gauge.
  • the US 5,291,131 A considers the expansion of a moving endless body such as B. a chain, a belt, a conveyor or the like, which is continuously measured by using two indices, e.g. B. pins or tongues, on the endless body and two sensors, e.g. B. magnetic or optical sensors, can be attached along the orbit of the endless body.
  • the sensors are connected to a computing circuit that determines the strain from the data provided by the sensors.
  • the JP 2018-047973 A relates to the provision of a device for measuring the elongation of a conveyor belt, which is capable of correctly measuring the elongation of a conveyor belt in a circumferential direction even when the conveyor belt meanders.
  • a device for measuring the elongation of a conveyor belt which is capable of correctly measuring the elongation of a conveyor belt in a circumferential direction even when the conveyor belt meanders.
  • two magnetic elements which are arranged at a distance in a belt circumferential direction of a conveyor belt
  • a magnetic sensor which is arranged opposite an outer peripheral surface of the conveyor belt and serves to detect a magnetic field that the two magnetic elements generate
  • a calculation part for calculating the elongation of the conveyor belt Conveyor belt in the belt circumferential direction based on an output signal from the magnetic sensor.
  • the calculation part calculates a ratio between the length of the magnetic elements in the tape running direction, which is calculated based on the output signal of the magnetic sensor, and the length of the magnetic elements in the tape circumferential direction, which is actually measured in advance, and corrects a distance in the tape running direction therebetween the two magnetic elements, which is calculated based on the output signal of the magnetic sensor using the ratio.
  • the CN 104692078 B describes a method for monitoring the running condition of a conveyor belt, comprising: attaching a plurality of detection elements Signal receiving and transmitting functions within or on the surface of the conveyor belt, and each sensing element stores identification information to identify its identity information.
  • a reading device is also provided, which is arranged on one side of the conveyor belt. In the step of parameter acquisition, when the conveyor belt is running, the reader reads the identification information of the detection element, records the detection time, and detects the identification between the reader and the detection element.
  • the DE 10 2013 111 191 A1 describes a method for contactless monitoring of a conveyor belt for damage, the conveyor belt having a plurality of electrically conductive inserts that extend at least partially in the transverse direction, the method with the steps: sending a first electromagnetic signal to the conveyor belt, and in a first state at least one electrically conductive insert, reflecting the first electromagnetic signal through the at least one electrically conductive insert as a second electromagnetic signal and receiving the second electromagnetic signal from the conveyor belt, and in a second state of the at least one electrically conductive insert, not receiving the second electromagnetic Signal from the conveyor belt.
  • the DE 199 02 759 A1 describes a monitoring device consisting of four reference marks, two addresses for identifying a measuring point and four sensor heads.
  • the sensor heads are arranged above the supporting side of the conveyor belt.
  • the conveyor belt typically consists of a rubber or rubber-like material with embedded reinforcing elements.
  • a measuring device is provided to record the belt temperature and the ambient temperature.
  • the DE 10 2010 002 551 A1 describes a belt for transmitting a drive movement with a belt body made of an elastic material and with a carcass which extends in the longitudinal direction of the belt and is at least partially surrounded by the belt body in order to increase the strength of the belt body in the longitudinal direction of the belt, a data memory being arranged in the belt body for storing data, whereby as data at least one belt-identifying information in the Data memory is stored, wherein the drive movement can be stopped and / or released depending on the belt-identifying information.
  • the DE 10 2011 051 923 A1 describes a device for continuous and non-destructive monitoring of a conveyor system with the following components: an endlessly closed conveyor belt with a load-side cover plate and a running-side cover plate, each made of a polymeric material with elastic properties and with an embedded tension member; Drums, support rollers and support frames, the aforementioned components in conjunction with the conveyor belt forming a material-conveying upper run with a feed point and delivery point for the conveyed material and a material-conveying or material-free lower run; a conductor loop package with endless closed conductor loops embedded in the conveyor belt; and an electronic slot protection system for contactless detection of damage to the conveyor belt, the slot protection system being an electrical device system that includes at least one interrogation station and at least one slot monitoring station and is connected to a central control that controls the entire conveyor system.
  • the device is equipped with sequential conductor loops and a sequential slot protection system as part of a conductor loop package, with the relevant functional logic being described in detail.
  • the invention is therefore based on the object of providing a system with which reliable and robust detection of an elongation of a belt - even during operation - can be ensured.
  • a system for determining the longitudinal elongation of a belt.
  • the system has a belt, a drive device, a transmitter and an evaluation unit.
  • the drive device has several pulleys.
  • the evaluation unit can be combined with the transmitter.
  • the belt has a base material, a reinforcement, a first ferromagnetic marking part and a second ferromagnetic marking part.
  • the base material can be at least partially formed, for example, from rubber material or polyurethane material.
  • the base material is made of rubber material.
  • the belt is in a circumferential direction of the Belt is designed in a ring-shaped circumferential manner. In addition, the belt wraps at least partially around the pulleys.
  • the belt can be driven in the circumferential direction from the drive direction.
  • the strength member of the belt is designed as a continuous cord that is wound helically in the circumferential direction and is embedded in the base material of the belt.
  • the first marking part and the second marking part are each embedded in the base material and/or attached to the base material.
  • the transmitter of the system is designed to generate a first, alternating electromagnetic field, which is referred to as the alternating reference field.
  • the first ferromagnetic marking part is designed to change the alternating reference field into a second, alternating electromagnetic field when the alternating reference field acts on the first ferromagnetic marking part.
  • the second alternating electromagnetic field is referred to as the first alternating reaction field.
  • the second ferromagnetic marking part is designed to change the alternating reference field into a third, alternating electromagnetic field when the alternating reference field acts on the second ferromagnetic marking part.
  • the third, alternating electromagnetic field is referred to as the second alternating reaction field.
  • the second marking part is arranged at a predetermined reference distance in the circumferential direction behind the first marking part, at least in an unloaded state of the belt.
  • the transmitter is arranged without contact with the belt in such a way that the first marking part and the second marking part can be guided past the transmitter one after the other by means of the belt and can be passed through the alternating reference field, which results in the alternating reference field acting one after the other on the first marking part and the second marking part .
  • the transmitter is also designed to detect the first alternating reaction field and an associated first detection time when the first marking part is moved past the transmitter.
  • the transmitter is designed to detect the second alternating reaction field and the associated second detection time when the second marking part is guided past the transmitter.
  • the system and in particular the associated transmitter and/or the associated evaluation unit, is configured to determine a belt speed of the belt in the circumferential direction based on the first alternating reaction field and/or the second alternating reaction field.
  • the evaluation unit is configured to determine a longitudinal elongation of the belt based on the To determine the reference distance, the belt speed, the first detection time and the second detection time.
  • the first and second marking parts are designed to be at least indirectly connected to one another by means of connecting webs, so that the predetermined reference distance can be reliably ensured in the unloaded state of the belt between the two marking parts in the circumferential direction.
  • the system offers the advantage that longitudinal stretching of the belt can be determined using the transmitter and the evaluation unit.
  • the transmitter can also be referred to and/or designed as a transmitter unit.
  • the system's belt is particularly robust against high temperatures and/or other mechanical, external influences.
  • an alternating reference field can be generated through which the belt, driven by the drive device, can be moved, so that the first marking part and the second marking part of the belt are moved one after the other through the alternating reference field.
  • Each of the two marking parts can be designed for coupling into the alternating reference field. This makes it possible for the alternating reference field to be changed into the first alternating reaction field when the first marking part is moved through the alternating reference field and thereby acts on the alternating reference field.
  • the second marking part that the alternating reference field changes into the second alternating reaction field when the second marking part is guided through the alternating reference field and thereby acts on the alternating reference field.
  • the reference alternating field, the first alternating reaction field and the second alternating reaction field do not exist at the same time. Rather, only one of the aforementioned alternating fields can exist at any given time.
  • a first detection time is recorded by the transmitter when the first alternating reaction field is detected by the transmitter. This occurs when the first marking part is guided past the transmitter, which is designed to generate the alternating reference field. However, by passing the first marking part, the first marking part is coupled into the alternating reference field, which leads to a change in the alternating reference field into the first alternating reaction field. This change occurs at the first detection time detected by the transmitter.
  • the second marking part or the second detection time At least in the unloaded state of the belt, the second marking part is at the predetermined reference distance arranged in the circumferential direction behind the first marking part. If the belt is driven in the circumferential direction by means of the drive device, the first marking part first moves through the alternating reference field and then the second marking part. When the second marking part is guided past the transmitter, the second marking part is coupled into the alternating reference field, which leads to the change of the alternating reference field into the second alternating reaction field.
  • the transmitter is designed to detect this second alternating reaction field and the associated second detection time.
  • first and second marking parts In principle, it is possible for the first and second marking parts to have the same design. However, the two marking parts can also be designed differently.
  • the system is configured to determine the belt speed of the belt in the circumferential direction based on the first alternating reaction field or the second alternating reaction field.
  • the transmitter which is designed to determine the belt speed of the belt in the circumferential direction based on the first alternating reaction field and/or the second alternating reaction field.
  • the transmitter can be designed as a magnetoresistive transmitter and/or include the function of a magnetoresistive sensor.
  • the second marking part is arranged at a predetermined reference distance in the circumferential direction behind the first marking part.
  • the belt is not in the unloaded state, but rather, for example, in a loaded state in which a tensile force acts on the belt, in particular on a tension strand of the belt, the distance between the second marking part and the first marking part increases in the circumferential direction .
  • the distance between the first detection time and the second detection time increases at the same belt speed when the belt changes from the unloaded state to the previously explained loaded state.
  • the elongation of the belt in the circumferential direction which is also referred to as the longitudinal elongation of the belt, can be deduced from the first and second detection times, the belt speed and the reference distance.
  • the evaluation unit is configured to determine a longitudinal elongation of the belt based on the reference distance, the belt speed, the first detection time and the second detection time.
  • the longitudinal elongation of the belt To determine the longitudinal elongation of the belt, no mechanical intervention in the belt is required during operation of the belt. Rather, the longitudinal elongation of the belt can be recorded without contact during operation of the belt.
  • the first marking part and the second marking part which are each embedded in the base material of the belt, offer the advantage that the determination of the longitudinal elongation of the belt is possible in a particularly precise and/or robust manner against temperature influences, even at a high temperature of the belt. Because the first and second marking parts are embedded in the base material, the determination of the longitudinal elongation of the belt is also particularly robust against possible mechanical influences that can act on the belt.
  • the elongation is preferably a relative elongation.
  • the longitudinal stretch of the belt can therefore be a relative stretch of the belt in the longitudinal direction.
  • each of the two ferromagnetic marking parts causes a change in the alternating reference field.
  • the change does not necessarily take place uniformly over the entire frequency band of the reference alternating field. Rather, it is possible for each of the two ferromagnetic marking parts to be designed to change a predetermined frequency range, so that the change in the alternating reference field caused thereby is characteristic and/or representative of the respective marking part.
  • Each marking part therefore preferably causes an associated change in the alternating reference field, so that a corresponding alternating reaction field, namely the first alternating reaction field or the second alternating reaction field, arises from the interaction of the alternating reference field with the respective marking part.
  • each capture time may also be referred to as a capture time.
  • Each detection time preferably represents the time of the maximum change in the respective reference alternating field respective marking part.
  • a period of time can be determined from the two recording times, and the relative elongation of the belt can be deduced from the period, the belt speed and the reference distance.
  • the evaluation unit is preferably configured accordingly.
  • the transmitter and the evaluation unit can be formed by a common unit, which can also be referred to as a transmitter evaluation unit.
  • An advantageous embodiment of the system is characterized in that the evaluation unit is configured to determine a remaining service life of the belt based on a history of determined longitudinal stretches of the belt.
  • the evaluation unit can thus be designed to determine several longitudinal strains one after the other. The determination can take place at fixed intervals. However, it is also possible for the determination to be triggered by the detection of the second reaction alternating field.
  • the recorded longitudinal strains can be stored by the evaluation unit. Based on these determined longitudinal strains, the evaluation unit can therefore be configured to determine the remaining service life of the belt. A correspondingly determined remaining service life can be used to plan maintenance intervals and/or the replacement of the belt in advance.
  • a further advantageous embodiment of the system is characterized in that the first detection time represents a time of a maximum change in the alternating reference field by the first marking part, and in that the second detection time represents a time of a maximum change in the alternating reference field by the second marking part. If the first or second marking part is moved through the alternating reference field, the greatest change in the alternating reference field often occurs, for example, when the respective marking part is arranged centrally in the alternating reference field. The movement of the respective marking part to the central arrangement or the movement out of this central arrangement leads to a decrease in the change in the reference alternating field.
  • the first detection time represents the time of the maximum change in the first alternating reference field by the first marking part.
  • the second Detection time which is represented by the time of the maximum change in the reference alternating field by the second marking part.
  • a further advantageous embodiment of the system is characterized in that the transmitter, in particular as part of a transmitter evaluation unit, is arranged contact-free on a strand of the belt.
  • the strand can be formed by a tension strand of the belt.
  • a further advantageous embodiment of the system is characterized in that the transmitter, in particular as part of the transmitter evaluation unit, is arranged at a distance of between 1 mm and 50 cm from the strand of the belt. This is preferably a tension strand of the belt.
  • the predetermined distance can ensure that the transmitter has no direct mechanical contact with the belt. This means that the longitudinal stretching of the belt can be carried out during operation without any negative mechanical influence on the belt. Because the predetermined distance is between 1 mm and 50 cm, it can also be ensured that electromagnetic interference only has a negligible influence on the detection of the first and/or second alternating reaction field. This makes it possible to detect the first or second alternating reaction field in a very robust manner to disturbance variables.
  • a further advantageous embodiment of the system is characterized in that the reference distance is smaller than the smallest span length of the belt.
  • the second marking part is arranged behind the first marking part at the reference distance in the circumferential direction of the belt when the belt is in an unloaded state.
  • the smallest strand length of the belt preferably refers to the smallest of the at least one strand length of the at least one tension strand of the belt.
  • the system it is also possible for the system to be designed in such a way that the reference distance is smaller than one is the strand length of any tension strand of the belt. The reference distance is therefore determined in such a way that during rotation of the belt there is at least one point in time at which both the first marking part and the second marking part are arranged in the same tension strand.
  • the distance between the two marking parts can be greater than the reference distance. However, this is usually only the case in a single-digit percentage range. Therefore, it can also be assumed that even in the event of a tensile load, the requirement is met that both marking parts are arranged simultaneously in the same tension strand at at least one point in time when the belt is rotating.
  • the two marking parts can be moved one after the other through the reference alternating field, which enables the previously explained determination of the longitudinal elongation of the belt.
  • the determined longitudinal elongation of the belt represents the longitudinal elongation of the belt in the tension strand. This is particularly interesting and/or representative.
  • the tension strand is often where the greatest load and/or the greatest tensile load on the belt occurs.
  • This load or the longitudinal stretch of the belt recorded there can therefore be advantageously used for further evaluation and/or for further predictions about the condition of the belt.
  • the stretch state of a slack strand of the belt is of interest.
  • the reference distance between the marking arrows is smaller than a span length of an empty span. The system can then be used to determine, for example, the longitudinal elongation of the slack strand, in particular due to a pretension of the belt. This can also be of interest in practice.
  • a further advantageous embodiment of the system is characterized in that the reference distance is a maximum of 90%, a maximum of 80%, a maximum of 70%, a maximum of 60% or a maximum of 50% of a span length of the belt.
  • This is preferably the shortest strand length and/or the strand length of the tension strand, in particular the shortest tension strand.
  • each marking part is designed to be passive, in particular purely passive.
  • Each of the two marking parts can therefore be designed as a passive, ferromagnetic marking part.
  • the passive design of the respective marking part is sufficient to change the reference alternating field, since the ferromagnetic material of the respective marking part can cause an induction-based change in the alternating field due to the arrangement in the reference alternating field.
  • Neither of the two marking parts is therefore coupled to other electronic components. Rather, it is preferably provided that each of the two marking parts is completely embedded in the base material of the belt, so that each of the two marking parts is completely covered by the base material.
  • each of the two marking parts is arranged without contact with the strength member of the belt and/or other possible components of the belt.
  • This offers the advantage that no friction effect occurs between the strength member of the belt and one of the two marking parts, even when the belt is under greater load.
  • This can effectively ensure that no friction and/or wear of the belt is caused by embedding the marking parts in the base material of the belt.
  • the belt is therefore particularly robust.
  • each marking part is designed as a rod-shaped marking part or as a film-shaped marking part.
  • each marking part extends with its greatest extent transversely to the circumferential direction of the belt.
  • the longitudinal axis of each rod-shaped marking part can be arranged transversely to the circumferential direction.
  • the film-shaped marking part there is also the possibility that the film has a greatest extent in a direction that is arranged transversely to the circumferential direction.
  • each marking part extends from one side wall to the opposite side wall of the belt. Each sidewall may be located on a corresponding side flank of the belt.
  • each marking part can extend at least substantially completely in the transverse direction from one side wall to the opposite side wall.
  • an extension length of each Marking part is between 95% and 70% of the distance between the two side walls. This can effectively ensure that each marking part is spaced at least a small distance inwards from the respective outside. As a result, electromagnetic influence on the marking parts can be prevented and/or insulation of the marking parts can be ensured particularly effectively by the base material.
  • Each marking part can, for example, have a diameter and/or a thickness of 5 ⁇ m to 0.5 mm. This has a negligible influence on the stiffness of the belt.
  • each marking part is prefabricated.
  • a correspondingly prefabricated marking part can therefore be embedded particularly easily into the base material of the belt when producing the belt.
  • each marking part is designed as a printed marking part.
  • the marking part can be formed by a printed, ferromagnetic metal marking part.
  • the marking part it is also possible for the marking part to be formed by a material mixture of ferromagnetic material and another printable material.
  • each marking part can be printed at a designated location in order to then completely embed the respective marking part into the rubber material. This makes it possible to embed the respective marking part in the rubber material in a particularly simple and at the same time precise manner.
  • each marking part is formed in one piece. This makes it possible for each marking part to be completely embedded in the belt, surrounded by the base material. Due to the base material, each marking part can thus be arranged separately from the other possible components in the belt and/or designed to be electrically insulated from the remaining belt.
  • the two marking parts can be arranged separately due to their one-piece design, preferably at the reference distance from one another.
  • An embodiment of the system according to the invention is characterized in that the first marking part and the second marking part are designed to be at least indirectly connected to one another.
  • Connecting webs can extend between the first and second marking parts, for example in the circumferential direction. Through these connecting webs, the first and second marking parts can have a mechanically fixed connection to one another.
  • the connecting webs are preferably designed to be electrically insulating.
  • the first and second marking parts as well as the connecting webs can be arranged in the form of a rectangular frame. As a result, the reference distance between the two marking parts in the circumferential direction can be ensured particularly reliably.
  • the corresponding frame with the first and second marking parts as well as the connecting webs can be embedded in the base material in order to then vulcanize the base material, for example.
  • the reference distance can be maintained through the connecting webs.
  • the reference distance between the first and second marking parts when the belt is in an unloaded state can therefore be guaranteed particularly reliably.
  • the connecting webs can be designed to be electrically insulating or electrically conductive. Even with an electrically conductive design of the connecting webs, it has been found in practice that each of the two marking parts causes a recognizable, associated change in the reference magnetic field, which leads to the first or second alternating reaction field. It is therefore also possible for the first and second marking parts as well as the two connecting webs to be designed as a connected and/or one-piece frame.
  • the system 2 has a belt 4 and a drive device 6 with, for example, two pulleys 8, 10.
  • One of the two pulleys 8, 10 can be coupled as a driving pulley to a motor of the drive device.
  • the belt 4 is designed to be annular in the circumferential direction U and partially wraps around each of the two pulleys 8, 10. The belt 4 can therefore be driven by the drive device 6 with the two pulleys 8, 10, so that the belt 4 rotates in the circumferential direction U.
  • the belt 4 has a base material 16 and at least one reinforcement 18. Purely by way of example, it is assumed below that the belt 4 has a strength member 18.
  • the base material 16 can, for example, be formed partially or completely from rubber material or partially or completely from polyurethane material. However, other materials for the base material 16 may also be provided.
  • the base material 16 is preferably designed to be electrically insulating.
  • the reinforcement 18 is embedded in the base material 16 as a continuous cord 24 that is wound helically in the circumferential direction U.
  • the strength member 18 serves to transmit forces in the circumferential direction U of the belt 4.
  • the strength member 18 can be formed, for example, from a metallic wire or from a plastic filament strand, such as a plastic fiber strand made of polyamide.
  • the individual turns of the cord 24 forming the reinforcement 18 can be arranged distributed relative to one another in the transverse direction Q of the belt 4. Each of the turns extends in the circumferential direction U.
  • the belt 4 also has a first ferromagnetic marking part 20 and a second ferromagnetic marking part 22.
  • the first ferromagnetic marking part 20 is also briefly referred to as the first marking part 20.
  • the second ferromagnetic marking part 22 is also briefly referred to as the second marking part 22.
  • the first marking part 20 and the second marking part 22 are each embedded in the base material 16 of the belt 4.
  • the two marking parts 20, 22 can be embedded in the base material 16 above the reinforcement 18. In principle, it is also possible for the two marking parts 20, 22 to be embedded in the base material 16 below the reinforcement 18.
  • there is the possibility that the two marking parts 20, 22 are arranged on an outside 44 of the belt 4. This design is in the Figure 2 not shown.
  • the outside 44 can be, for example, the so-called back of the belt 4.
  • Each of the two ferromagnetic marking parts 20, 22 can be formed completely or at least partially from ferromagnetic material and/or substance.
  • ferromagnetic material and/or substance For example, iron, nickel or cobalt are substances with ferromagnetic properties.
  • alloys with ferromagnetic properties are often used.
  • Corresponding alloys can be, for example, ALNiCo, SmCo or NiFeCo alloys.
  • Each of the two marking parts 20, 22 can therefore be, for example, a ferromagnetic metal marking part or a ferromagnetic alloy metal marking part.
  • the second marking part 22 is arranged at a predetermined reference distance R in the circumferential direction U behind the first marking part 20. This is preferably the average distance between the two marking parts 20, 22 in the unloaded state of the belt 4.
  • each of the two marking parts 20, 22 is designed as a rod-shaped marking part 20, 22.
  • Each of the two marking parts 20, 22 can therefore extend in the transverse direction Q from a first side wall 46 of the belt 4 to an opposite side wall 48 of the belt 4.
  • each of the two marking parts 20, 22 is shorter than the distance in the transverse direction between the two side walls 46, 48. This can ensure that each of the two marking parts 20, 22 is completely embedded in the base material 16 of the belt 4.
  • the second marking part 22 is arranged parallel to the first marking part 20.
  • the reference distance R between the two marking parts 20, 22 is preferably only present in the unloaded state of the belt.
  • tensile forces act on the belt 4 in the circumferential direction U, which causes the belt 4 to stretch in the circumferential direction U.
  • the quotient of the measuring distance M and the reference distance R is representative of the longitudinal elongation of the belt.
  • the longitudinal elongation of the belt is a relative elongation of the belt 4.
  • the longitudinal elongation of the belt is preferably determined by the ratio of the measuring distance M to the reference distance R.
  • detection of the two marking parts 20, 22 is only possible indirectly.
  • the system therefore has a transmitter 12 and an evaluation unit 14.
  • the transmitter 12 and the evaluation unit 14 can be combined and/or assigned to a common device 50.
  • the device 50 can thus have and/or form the transmitter 12 and the evaluation unit 14.
  • the transmitter 12 is arranged at a predetermined distance A from the belt 4.
  • the transmitter 12 can be arranged at a distance A between 1 mm and 50 cm from a tension strand 52 of the belt 4.
  • the transmitter 12 can face the back or the outside 44 of the belt 4.
  • predetermined distance A ensures particularly easily that the transmitter 12 is arranged contact-free on the strand 32, in particular the tension strand 52, of the belt 4.
  • the transmitter 12 is designed to generate a first alternating electromagnetic field, which is referred to as the reference alternating field 26.
  • the reference alternating field 26 is in Figure 1 indicated schematically by magnetic field lines.
  • the alternating reference field 26 penetrates the belt 4.
  • the belt 4 is driven by the drive device 6. This ensures that the first marking part 20 and the second marking part 22 are moved one after the other in the circumferential direction U through the reference alternating field 26.
  • the magnetic field strength Y is shown as an example and schematically as a function of the frequency f of the reference magnetic field 26.
  • the frequency response shown is not intended to be limiting.
  • the first ferromagnetic marking part 20 is designed to change the reference alternating field 26 into the first alternating reaction field when the alternating reaction field acts on the first ferromagnetic marking part 20, or vice versa.
  • the interaction between the alternating reference field 26 and the first marking part 20 creates the first alternating reaction field from the alternating reference field. This represents a change compared to the original alternating reference field 26.
  • the first marking part 20 and the second marking part 22 are guided past the transmitter 12 one after the other, so that initially the first marking part 20 causes the first alternating reaction field through the interaction with the reference alternating field 26.
  • the transmitter 12 is designed to detect the first alternating reaction field and an associated first detection time T1 when the first marking part 20 is guided past the transmitter 12.
  • the average field strength H of the alternating field in the area between the belt 4 and the transmitter 12 is shown schematically. If a belt area without one of the two marking parts is moved through the reference alternating field 26, there is at least essentially no change in the average field strength H. However, if the first marking part 20 with the belt 4 is guided through the reference alternating field 26, the average field strength H changes in the area 28, which is referred to as the first change in the field strength H. After the first marking part 20 is guided past the transmitter 12, the average field strength H again at least essentially assumes the previous value.
  • the second ferromagnetic marking part 22 is designed to change the alternating reference field 26 into the second alternating reaction field when the alternating reference field 26 acts on the second marking part 22, or vice versa.
  • the interaction between the alternating reference field 26 and the second marking part 22 creates the first alternating reaction field 26 from the alternating reference field. This represents a change compared to the alternating reference field 26.
  • a corresponding change in the area 30 in the Figure 6 therefore also shows the corresponding change in the average field strength H. This is caused by the movement of the second marking part 22 through the alternating reference field 26.
  • the transmitter 12 is designed to detect the second alternating reaction field and the associated second detection time T2 when the second marking part 22 is guided past the transmitter 12.
  • the belt 4 is driven by the drive device 6 at a belt speed in the circumferential direction U. If, for example, the belt speed of the belt 4 is assumed to be constant, the time interval between the first detection time T1 and the second detection time T2 increases when the speed on the belt 4 increases Increase the tensile forces acting in the circumferential direction U. By increasing the tensile forces, the measuring distance M between the second marking part 22 and the first marking part 20 is increased. Corresponding to the increased measuring distance 11, the time interval between the second detection time T2 and the first detection time T1 also increases.
  • the system 2 is also configured to determine the belt speed of the belt 4 in the circumferential direction U based on the first alternating reaction field and/or the second alternating reaction field.
  • the transmitter 12 can be designed as or have a magnetoresistive sensor.
  • the transmitter 12 of the system 2 is designed to determine the belt speed of the belt 4 in the circumferential direction U based on the first alternating reaction field and/or the second alternating reaction field.
  • the transmitter 12 is coupled to the evaluation unit 14, in particular via a signal line. This means that the measurement variables recorded by the transmitter 12 are available to the evaluation unit.
  • the evaluation unit 14 is configured to determine a longitudinal elongation of the belt 4 based on the reference distance R, the belt speed, the first detection time T1 and the second detection time T2. For this purpose, the following formula can be stored in the evaluation unit 14.
  • the transmitter 12 faces the tension strand 52.
  • the reference distance R between the second marking part 22 and the first marking part 20 is smaller than the strand length B of the tension strand 52. It is therefore preferably provided that the reference distance R is a maximum of 70% or a maximum of 50% of the strand length W of the tension strand 52.
  • first marking part 20 is formed in one piece and that the second marking part 22 is formed in one piece.
  • FIG. 7 An inventive design of the two marking parts 20, 22 can be seen schematically from the section of the belt 4, as shown by way of example in the Figure 7 schematic is shown.
  • the front ends of the two marking parts 20, 22 are mechanically connected via connecting webs 38, 40 in such a way that the two marking parts 20, 22 and the two connecting webs 38, 40 are arranged in the manner of a frame 42 and/or are arranged circumferentially.
  • the two connecting webs 38, 40 can be designed to be electrically insulating.
  • a ferromagnetic frame 42 to form each of the two marking parts 20, 22 and each of the two connecting webs 38, 40.
  • the frame 42 or the connecting webs 38, 40 offer the advantage that the predetermined reference distance R between the two marking parts 20, 22 is particularly easily ensured in the unloaded state of the belt 4.

Description

Die Erfindung betrifft ein System zur Ermittlung einer Längsdehnung eines Riemens.The invention relates to a system for determining the longitudinal elongation of a belt.

Ein System, das einen Riemen und eine Antriebsvorrichtung für den Riemen aufweist, ist grundsätzlich aus dem Stand der Technik bekannt. Dabei weist die Antriebsvorrichtung mehrere, beispielsweise zwei Riemenscheiben auf. Der Riemen ist in einer Umfangsrichtung ringförmig umlaufend ausgebildet und umschlingt die Riemenscheiben zumindest teilweise. Außerdem ist der Riemen von der Antriebsvorrichtung in Umfangsrichtung antreibbar. Bei einem Riemen handelt es sich vorzugsweise um einen Antriebsriemen zur Übertragung von Zugkräften. Dabei ist ein Riemen oftmals einer Vorspannung, Nutzkräften, Fliehkräften und/oder Biegungen ausgesetzt.A system that has a belt and a drive device for the belt is basically known from the prior art. The drive device has several, for example two, pulleys. The belt is designed to run annularly in a circumferential direction and at least partially wraps around the pulleys. In addition, the belt can be driven in the circumferential direction by the drive device. A belt is preferably a drive belt for transmitting tensile forces. A belt is often exposed to pretension, useful forces, centrifugal forces and/or bends.

Die Lebensdauer von einem Riemen wird durch die Dehnung des Riemens, insbesondere die Dehnung in Umfangsrichtung, zumindest mitbestimmt. Die Umdrehungsrate, mit der sich der Riemen bewegt, und/oder die Leistung, die zum Antrieb des Riemens notwendig ist, kann über die Belastung des Riemens Aufschluss geben. Allerdings kann aus dieser Belastung nur eine grobe Abschätzung einer tatsächlich lokal auftretenden Dehnung des Riemens erfolgen. Eine genaue Bestimmung basierend auf der zuvor genannten Belastung ist nicht möglich.The service life of a belt is at least partly determined by the stretch of the belt, in particular the stretch in the circumferential direction. The rate of rotation at which the belt moves and/or the power required to drive the belt can indicate the load on the belt. However, this load can only be used to give a rough estimate of the actual local stretching of the belt. An exact determination based on the aforementioned load is not possible.

Aus dem Stand der Technik sind Dehnungsmessstreifen bekannt. Die Verwendung eines Dehnungsmessstreifens bedarf jedoch einer elektrischen Messschaltung, die mit dem Dehnungsmessstreifen zu koppeln ist, um eine von dem Dehnungsmessstreifen erfasste Dehnung auszuwerten bzw. ein entsprechendes Auswertungssignal bereitzustellen. Um einen Dehnungsmessstreifen deshalb für einen Riemen zu verwenden, bedarf es ebenfalls der Befestigung der zuvor genannten Auswertungsschaltung an dem Riemen. Insbesondere wenn der Riemen während des Gebrauchs einer hohen Temperatur ausgesetzt ist, die beispielsweise durch Reibung des Riemens an einer Umlenkscheibe und/oder durch eine hohe Umgebungstemperatur beeinflusst ist, ist eine robuste Auswerteschaltung nur mit sehr hohem technischen Aufwand und entsprechenden Kosten herstellbar, die bei entsprechend hohen Temperaturen eine verlässliche Messung der Dehnung mittels des Dehnungsmessstreifens gewährleistet.Strain gauges are known from the prior art. However, the use of a strain gauge requires an electrical measuring circuit that is to be coupled to the strain gauge in order to evaluate a strain detected by the strain gauge or to provide a corresponding evaluation signal. In order to use a strain gauge for a belt, you also need one Attachment of the aforementioned evaluation circuit to the belt. In particular, if the belt is exposed to a high temperature during use, which is influenced, for example, by friction of the belt on a deflection pulley and/or by a high ambient temperature, a robust evaluation circuit can only be produced with very high technical effort and corresponding costs High temperatures ensure reliable measurement of the strain using the strain gauge.

Die US 5,291,131 A betrachtet die Dehnung eines sich bewegenden Endloskörpers wie z. B. einer Kette, eines Riemens, eines Förderers oder dergleichen, welche kontinuierlich gemessen wird, indem zwei Indizes, z. B. Stifte oder Zungen, auf dem Endloskörper und zwei Sensoren, z. B. magnetische oder optische Sensoren, entlang der Umlaufbahn des Endloskörpers angebracht werden. Die Sensoren sind an eine Rechenschaltung angeschlossen, die aus den von den Sensoren gelieferten Daten die Dehnung ermittelt.The US 5,291,131 A considers the expansion of a moving endless body such as B. a chain, a belt, a conveyor or the like, which is continuously measured by using two indices, e.g. B. pins or tongues, on the endless body and two sensors, e.g. B. magnetic or optical sensors, can be attached along the orbit of the endless body. The sensors are connected to a computing circuit that determines the strain from the data provided by the sensors.

Die JP 2018-047973 A betrifft die Bereitstellung einer Vorrichtung zur Messung der Dehnung eines Förderbandes, die in der Lage ist, die Dehnung eines Förderbandes in einer Umfangsrichtung auch dann korrekt zu messen, wenn das Förderband mäandert. Hierzu sind zwei Magnetelemente, die mit einem Abstand in einer Bandumfangsrichtung eines Förderbandes angeordnet sind, ein Magnetsensor, der gegenüber einer äußeren Umfangsfläche des Förderbandes angeordnet ist und zum Erfassen eines Magnetfeldes dient, das die beiden Magnetelemente erzeugen, und ein Berechnungsteil zum Berechnen der Dehnung des Förderbandes in der Bandumfangsrichtung auf der Grundlage eines Ausgangssignals von dem Magnetsensor vorgesehen. Der Berechnungsteil berechnet ein Verhältnis zwischen der Länge der magnetischen Elemente in der Bandlaufrichtung, die basierend auf dem Ausgangssignal des Magnetsensors berechnet wird, und der Länge der magnetischen Elemente in der Bandumfangsrichtung, die tatsächlich im Voraus gemessen wird, und korrigiert einen Abstand in der Bandlaufrichtung zwischen den zwei magnetischen Elementen, der basierend auf dem Ausgangssignal des Magnetsensors berechnet wird, unter Verwendung des Verhältnisses.The JP 2018-047973 A relates to the provision of a device for measuring the elongation of a conveyor belt, which is capable of correctly measuring the elongation of a conveyor belt in a circumferential direction even when the conveyor belt meanders. For this purpose, two magnetic elements which are arranged at a distance in a belt circumferential direction of a conveyor belt, a magnetic sensor which is arranged opposite an outer peripheral surface of the conveyor belt and serves to detect a magnetic field that the two magnetic elements generate, and a calculation part for calculating the elongation of the conveyor belt Conveyor belt in the belt circumferential direction based on an output signal from the magnetic sensor. The calculation part calculates a ratio between the length of the magnetic elements in the tape running direction, which is calculated based on the output signal of the magnetic sensor, and the length of the magnetic elements in the tape circumferential direction, which is actually measured in advance, and corrects a distance in the tape running direction therebetween the two magnetic elements, which is calculated based on the output signal of the magnetic sensor using the ratio.

Das CN 104692078 B beschreibt ein Verfahren zur Überwachung des Laufzustandes eines Förderbandes, umfassend: Anbringen einer Vielzahl von Erfassungselementen mit Signalempfangs- und -sendefunktionen innerhalb oder auf der Oberfläche des Förderbandes, und jedes Erfassungselement speichert Identifikationsinformationen zur Identifizierung seiner Identitätsinformationen. Es ist auch ein Lesegerät vorgesehen, das auf einer Seite des Förderbandes angeordnet ist. Im Schritt der Parametererfassung, wenn das Förderband läuft, liest das Lesegerät die Identifikationsinformationen des Erfassungselements, zeichnet die Erfassungszeit auf und erfasst die Identifikation zwischen dem Lesegerät und dem Erfassungselement.The CN 104692078 B describes a method for monitoring the running condition of a conveyor belt, comprising: attaching a plurality of detection elements Signal receiving and transmitting functions within or on the surface of the conveyor belt, and each sensing element stores identification information to identify its identity information. A reading device is also provided, which is arranged on one side of the conveyor belt. In the step of parameter acquisition, when the conveyor belt is running, the reader reads the identification information of the detection element, records the detection time, and detects the identification between the reader and the detection element.

Die DE 10 2013 111 191 A1 beschreibt ein Verfahren zur berührungslosen Überwachung eines Fördergurtes auf Beschädigung, wobei der Fördergurt eine Mehrzahl von elektrisch leitfähigen Einlagen aufweist, die sich zumindest teilweise in Querrichtung erstrecken, das Verfahren mit den Schritten: Aussenden eines ersten elektromagnetischen Signals an den Fördergurt, und in einem ersten Zustand wenigstens einer elektrisch leitfähigen Einlage, Reflektieren des ersten elektromagnetischen Signals durch die wenigstens eine elektrisch leitfähige Einlage als zweites elektromagnetischen Signals und Empfangen des zweiten elektromagnetischen Signals von dem Fördergurt, und in einem zweiten Zustand der wenigstens einen elektrisch leitfähigen Einlage, Nicht-Empfangen des zweiten elektromagnetischen Signals von dem Fördergurt.The DE 10 2013 111 191 A1 describes a method for contactless monitoring of a conveyor belt for damage, the conveyor belt having a plurality of electrically conductive inserts that extend at least partially in the transverse direction, the method with the steps: sending a first electromagnetic signal to the conveyor belt, and in a first state at least one electrically conductive insert, reflecting the first electromagnetic signal through the at least one electrically conductive insert as a second electromagnetic signal and receiving the second electromagnetic signal from the conveyor belt, and in a second state of the at least one electrically conductive insert, not receiving the second electromagnetic Signal from the conveyor belt.

Die DE 199 02 759 A1 beschreibt eine Überwachungseinrichtung bestehend aus vier Referenzmarken, zwei Adressen zur Identifizierung einer Messstelle und vier Sensorköpfen. Die Sensorköpfe sind oberhalb der Tragseite des Förderbandes angeordnet. Das Förderband besteht typischerweise aus einem Gummi oder gummiähnlichen Material mit eingebetteten Verstärkungselementen. Zur Erfassung der Gurttemperatur und der Umgebungstemperatur ist eine Messeinrichtung vorgesehen.The DE 199 02 759 A1 describes a monitoring device consisting of four reference marks, two addresses for identifying a measuring point and four sensor heads. The sensor heads are arranged above the supporting side of the conveyor belt. The conveyor belt typically consists of a rubber or rubber-like material with embedded reinforcing elements. A measuring device is provided to record the belt temperature and the ambient temperature.

Die DE 10 2010 002 551 A1 beschreibt einen Riemen zur Übertragung einer Antriebsbewegung mit einem Riemenkörper aus einem elastischen Werkstoff und mit einer in Riemenlängsrichtung erstreckten und von dem Riemenkörper zumindest abschnittsweise umgebenen Karkasse zur Erhöhung der Festigkeit des Riemenkörpers in Riemenlängsrichtung, wobei in dem Riemenkörper ein Datenspeicher angeordnet ist zur Speicherung von Daten, wobei als Daten wenigstens eine riemenidentifizierende Information in dem Datenspeicher gespeichert ist, wobei die Antriebsbewegung in Abhängigkeit von der riemenidentifizierenden Information stillsetzbar und/oder freigebbar ist.The DE 10 2010 002 551 A1 describes a belt for transmitting a drive movement with a belt body made of an elastic material and with a carcass which extends in the longitudinal direction of the belt and is at least partially surrounded by the belt body in order to increase the strength of the belt body in the longitudinal direction of the belt, a data memory being arranged in the belt body for storing data, whereby as data at least one belt-identifying information in the Data memory is stored, wherein the drive movement can be stopped and / or released depending on the belt-identifying information.

Die DE 10 2011 051 923 A1 beschreibt eine Einrichtung zur kontinuierlichen und zerstörungsfreien Überwachung einer Förderanlage mit folgenden Bauteilen: einem endlos geschlossenen Fördergurt mit einer tragseitigen Deckplatte und laufseitigen Deckplatte aus jeweils einem polymeren Werkstoff mit elastischen Eigenschaften sowie mit einem eingebetteten Zugträger; Trommeln, Tragrollen und Tragerüste, wobei die vorgenannten Bauteile in Verbindung mit dem Fördergurt ein materialförderndes Obertrum mit einer Aufgabestelle und Abgabestelle für das Fördermaterial und ein materialförderndes oder materialfreies Untertrum bilden; einem Leiterschleifen-Paket mit endlos geschlossenen Leiterschleifen, das im Fördergurt eingebettet ist; sowie einem elektronischen Schlitzschutzsystem zur berührungslosen Erfassung von Schäden des Fördergurtes, wobei das Schlitzschutzsystem ein elektrisches Gerätesystem ist, das wenigstens eine Abfragestation sowie wenigstens eine Schlitzüberwachungsstation umfasst und dabei an eine Zentralsteuerung angeschlossen ist, die die gesamte Förderanlage steuert. Die Einrichtung ist im Rahmen eines Leiterschleifen-Pakets mit sequentiellen Leiterschleifen und einem sequentiellen Schlitzschutzsystem ausgerüstet, wobei die diesbezügliche Funktionslogik detailliert beschrieben wird.The DE 10 2011 051 923 A1 describes a device for continuous and non-destructive monitoring of a conveyor system with the following components: an endlessly closed conveyor belt with a load-side cover plate and a running-side cover plate, each made of a polymeric material with elastic properties and with an embedded tension member; Drums, support rollers and support frames, the aforementioned components in conjunction with the conveyor belt forming a material-conveying upper run with a feed point and delivery point for the conveyed material and a material-conveying or material-free lower run; a conductor loop package with endless closed conductor loops embedded in the conveyor belt; and an electronic slot protection system for contactless detection of damage to the conveyor belt, the slot protection system being an electrical device system that includes at least one interrogation station and at least one slot monitoring station and is connected to a central control that controls the entire conveyor system. The device is equipped with sequential conductor loops and a sequential slot protection system as part of a conductor loop package, with the relevant functional logic being described in detail.

Der Erfindung liegt deshalb die Aufgabe zugrunde, ein System bereitzustellen, mit dem eine verlässliche und robuste Erfassung einer Dehnung eines Riemens - auch im Betrieb - gewährleistet werden kann.The invention is therefore based on the object of providing a system with which reliable and robust detection of an elongation of a belt - even during operation - can be ensured.

Gelöst wird die Aufgabe durch ein System mit den Merkmalen des Anspruchs 1. Vorgesehen ist also ein System zur Ermittlung einer Längsdehnung eines Riemens. Das System weist einen Riemen, eine Antriebsvorrichtung, einen Transmitter und eine Auswerteeinheit auf. Die Antriebsvorrichtung weist mehrere Riemenscheiben auf. Die Auswerteeinheit kann mit dem Transmitter kombiniert ausgebildet sein. Der Riemen weist ein Basismaterial, einen Festigkeitsträger, ein erstes ferromagnetisches Markierungsteil und ein zweites ferromagnetisches Markierungsteil auf. Das Basismaterial kann beispielsweise aus Gummimaterial oder Polyurethanmaterial zumindest teilweise gebildet sein. Vorzugsweise ist das Basismaterial aus Gummimaterial. Der Riemen ist in einer Umfangsrichtung des Riemens ringförmig umlaufend ausgebildet. Außerdem umschlingt der Riemen die Riemenscheiben jeweils zumindest teilweise. Der Riemen ist von der Antriebsrichtung in Umfangsrichtung antreibbar. Der Festigkeitsträger des Riemens ist als ein durchgängiger, in Umfangsrichtung schraubenförmig gewendelter Cord ausgebildet und in das Basismaterial des Riemens eingebettet. Das erste Markierungsteil und das zweite Markierungsteil sind jeweils in das Basismaterial eingebettet und/oder an dem Basismaterial befestigt. Der Transmitter des Systems ist zum Erzeugen eines ersten, elektromagnetischen Wechselfelds ausgebildet, das als Referenzwechselfeld bezeichnet ist. Das erste ferromagnetische Markierungsteil ist zur Veränderung des Referenzwechselfelds in ein zweites, elektromagnetisches Wechselfeld ausgebildet, wenn das Referenzwechselfeld auf das erste ferromagnetische Markierungsteil einwirkt. Das zweite elektromagnetische Wechselfeld wird als erstes Reaktionswechselfeld bezeichnet. Das zweite ferromagnetische Markierungsteil ist zur Veränderung des Referenzwechselfelds in ein drittes, elektromagnetisches Wechselfeld ausgebildet, wenn das Referenzwechselfeld auf das zweite ferromagnetische Markierungsteil einwirkt. Das dritte, elektromagnetische Wechselfeld wird als das zweite Reaktionswechselfeld bezeichnet. Das zweite Markierungsteil ist in einem vorbestimmten Referenzabstand in Umfangsrichtung hinter dem ersten Markierungsteil angeordnet, zumindest in einem unbelasteten Zustand des Riemens. Der Transmitter ist kontaktfrei zu dem Riemen derart angeordnet, so dass das erste Markierungsteil und das zweite Markierungsteil mittels des Riemens nacheinander an dem Transmitter vorbeiführbar und durch das Referenzwechselfeld hindurchführbar sind, was in einem Einwirken des Referenzwechselfelds nacheinander auf das erste Markierungsteil und das zweite Markierungsteil resultiert. Der Transmitter ist außerdem zur Erfassung des ersten Reaktionswechselfelds und einer zugehörigen, ersten Erfassungszeit ausgebildet, wenn das erste Markierungsteil an dem Transmitter vorbeigeführt wird. Außerdem ist der Transmitter zur Erfassung des zweiten Reaktionswechselfelds und der zugehörigen zweiten Erfassungszeit ausgebildet, wenn das zweite Markierungsteil an dem Transmitter vorbeigeführt wird. Das System, und insbesondere der zugehörige Transmitter und/oder die zugehörige Auswerteeinheit, ist konfiguriert, eine Riemengeschwindigkeit des Riemens in Umfangsrichtung basierend auf dem ersten Reaktionswechselfeld und/oder dem zweiten Reaktionswechselfeld zu ermitteln. Die Auswerteeinheit ist dazu konfiguriert, eine Längsdehnung des Riemens basierend auf dem Referenzabstand, der Riemengeschwindigkeit, der ersten Erfassungszeit und der zweiten Erfassungszeit zu ermitteln. Erfindungsgemäß sind das erste und zweite Markierungsteil zumindest indirekt miteinander mittels Verbindungsstege verbunden ausgebildet, so dass der vorbestimmte Referenzabstand in dem unbelasteten Zustand des Riemens zwischen den beiden Markierungsteilen in Umfangsrichtung sicher gewährleistet werden kann.The task is solved by a system with the features of claim 1. A system is therefore provided for determining the longitudinal elongation of a belt. The system has a belt, a drive device, a transmitter and an evaluation unit. The drive device has several pulleys. The evaluation unit can be combined with the transmitter. The belt has a base material, a reinforcement, a first ferromagnetic marking part and a second ferromagnetic marking part. The base material can be at least partially formed, for example, from rubber material or polyurethane material. Preferably the base material is made of rubber material. The belt is in a circumferential direction of the Belt is designed in a ring-shaped circumferential manner. In addition, the belt wraps at least partially around the pulleys. The belt can be driven in the circumferential direction from the drive direction. The strength member of the belt is designed as a continuous cord that is wound helically in the circumferential direction and is embedded in the base material of the belt. The first marking part and the second marking part are each embedded in the base material and/or attached to the base material. The transmitter of the system is designed to generate a first, alternating electromagnetic field, which is referred to as the alternating reference field. The first ferromagnetic marking part is designed to change the alternating reference field into a second, alternating electromagnetic field when the alternating reference field acts on the first ferromagnetic marking part. The second alternating electromagnetic field is referred to as the first alternating reaction field. The second ferromagnetic marking part is designed to change the alternating reference field into a third, alternating electromagnetic field when the alternating reference field acts on the second ferromagnetic marking part. The third, alternating electromagnetic field is referred to as the second alternating reaction field. The second marking part is arranged at a predetermined reference distance in the circumferential direction behind the first marking part, at least in an unloaded state of the belt. The transmitter is arranged without contact with the belt in such a way that the first marking part and the second marking part can be guided past the transmitter one after the other by means of the belt and can be passed through the alternating reference field, which results in the alternating reference field acting one after the other on the first marking part and the second marking part . The transmitter is also designed to detect the first alternating reaction field and an associated first detection time when the first marking part is moved past the transmitter. In addition, the transmitter is designed to detect the second alternating reaction field and the associated second detection time when the second marking part is guided past the transmitter. The system, and in particular the associated transmitter and/or the associated evaluation unit, is configured to determine a belt speed of the belt in the circumferential direction based on the first alternating reaction field and/or the second alternating reaction field. The evaluation unit is configured to determine a longitudinal elongation of the belt based on the To determine the reference distance, the belt speed, the first detection time and the second detection time. According to the invention, the first and second marking parts are designed to be at least indirectly connected to one another by means of connecting webs, so that the predetermined reference distance can be reliably ensured in the unloaded state of the belt between the two marking parts in the circumferential direction.

Das System bietet den Vorteil, dass auf eine Längsdehnung des Riemens mittels des Transmitters und der Auswerteeinheit geschlossen werden kann. Der Transmitter kann auch als Transmittereinheit bezeichnet und/oder ausgebildet sein. Darüber hinaus ist der Riemen des Systems besonders robust gegenüber hohen Temperaturen und/oder anderen mechanischen, äußeren Einflüssen.The system offers the advantage that longitudinal stretching of the belt can be determined using the transmitter and the evaluation unit. The transmitter can also be referred to and/or designed as a transmitter unit. In addition, the system's belt is particularly robust against high temperatures and/or other mechanical, external influences.

Mittels des Transmitters des Systems kann ein Referenzwechselfeld erzeugt werden, durch das der Riemen, angetrieben durch die Antriebsvorrichtung, hindurchbewegt werden kann, so dass das erste Markierungsteil und das zweite Markierungsteil des Riemens nacheinander durch das Referenzwechselfeld bewegt werden. Jedes der beiden Markierungsteile kann zur Einkopplung in das Referenzwechselfeld ausgebildet sein. Dadurch ist es möglich, dass das Referenzwechselfeld in das erste Reaktionswechselfeld verändert wird, wenn das erste Markierungsteil durch das Referenzwechselfeld bewegt wird und dabei auf das Referenzwechselfeld einwirkt. Entsprechendes gilt für das zweite Markierungsteil, dass das Referenzwechselfeld in das zweite Reaktionswechselfeld verändert, wenn das zweite Markierungsteil durch das Referenzwechselfeld geführt wird und dabei auf das Referenzwechselfeld einwirkt. An dieser Stelle sei darauf hingewiesen, dass das Referenzwechselfeld, das erste Reaktionswechselfeld und das zweite Reaktionswechselfeld nicht gleichzeitig bestehen. Vielmehr kann zu jedem Zeitpunkt nur eines der zuvor genannten Wechselfelder bestehen.By means of the transmitter of the system, an alternating reference field can be generated through which the belt, driven by the drive device, can be moved, so that the first marking part and the second marking part of the belt are moved one after the other through the alternating reference field. Each of the two marking parts can be designed for coupling into the alternating reference field. This makes it possible for the alternating reference field to be changed into the first alternating reaction field when the first marking part is moved through the alternating reference field and thereby acts on the alternating reference field. The same applies to the second marking part that the alternating reference field changes into the second alternating reaction field when the second marking part is guided through the alternating reference field and thereby acts on the alternating reference field. It should be noted at this point that the reference alternating field, the first alternating reaction field and the second alternating reaction field do not exist at the same time. Rather, only one of the aforementioned alternating fields can exist at any given time.

Von dem Transmitter wird eine erste Erfassungszeit erfasst, wenn von dem Transmitter das erste Reaktionswechselfeld erfasst ist. Dies tritt auf, wenn das erste Markierungsteil an dem Transmitter vorbeigeführt wird, der zur Erzeugung des Referenzwechselfelds ausgebildet ist. Durch das Vorbeiführen des ersten Markierungsteils wird jedoch das erste Markierungsteil in das Referenzwechselfeld eingekoppelt, was zur Veränderung des Referenzwechselfelds in das erste Reaktionswechselfeld führt. Diese Veränderung tritt zu der ersten Erfassungszeit auf, die von dem Transmitter erfasst wird. Entsprechendes gilt für das zweite Markierungsteil bzw. die zweite Erfassungszeit. Zumindest im unbelasteten Zustand des Riemens ist das zweite Markierungsteil in dem vorbestimmten Referenzabstand in Umfangsrichtung hinter dem ersten Markierungsteil angeordnet. Wird der Riemen in Umfangsrichtung mittels der Antriebsvorrichtung angetrieben, so bewegt sich zunächst das erste Markierungsteil durch das Referenzwechselfeld und danach das zweite Markierungsteil. Wenn das zweite Markierungsteil an dem Transmitter vorbeigeführt wird, findet eine Einkopplung des zweiten Markierungsteils in das Referenzwechselfeld statt, was zu der Veränderung des Referenzwechselfelds in das zweite Reaktionswechselfeld führt. Der Transmitter ist zur Erfassung dieses zweiten Reaktionswechselfelds und der zugehörigen zweiten Erfassungszeit ausgebildet.A first detection time is recorded by the transmitter when the first alternating reaction field is detected by the transmitter. This occurs when the first marking part is guided past the transmitter, which is designed to generate the alternating reference field. However, by passing the first marking part, the first marking part is coupled into the alternating reference field, which leads to a change in the alternating reference field into the first alternating reaction field. This change occurs at the first detection time detected by the transmitter. The same applies to the second marking part or the second detection time. At least in the unloaded state of the belt, the second marking part is at the predetermined reference distance arranged in the circumferential direction behind the first marking part. If the belt is driven in the circumferential direction by means of the drive device, the first marking part first moves through the alternating reference field and then the second marking part. When the second marking part is guided past the transmitter, the second marking part is coupled into the alternating reference field, which leads to the change of the alternating reference field into the second alternating reaction field. The transmitter is designed to detect this second alternating reaction field and the associated second detection time.

Grundsätzlich ist es möglich, dass das erste und zweite Markierungsteil gleich ausgebildet sind. Jedoch können die beiden Markierungsteile auch unterschiedlich ausgebildet sein.In principle, it is possible for the first and second marking parts to have the same design. However, the two marking parts can also be designed differently.

Außerdem ist das System konfiguriert, die Riemengeschwindigkeit des Riemens in Umfangsrichtung basierend auf dem ersten Reaktionswechselfeld oder dem zweiten Reaktionswechselfeld zu ermitteln. Dies gilt insbesondere für den Transmitter, der zur Ermittlung der Riemengeschwindigkeit des Riemens in Umfangsrichtung basierend auf dem ersten Reaktionswechselfeld und/oder dem zweiten Reaktionswechselfeld ausgebildet ist. Der Transmitter kann dazu als magnetoresistiver Transmitter ausgebildet sein und/oder die Funktion eines magnetoresistiven Sensors umfassen.Additionally, the system is configured to determine the belt speed of the belt in the circumferential direction based on the first alternating reaction field or the second alternating reaction field. This applies in particular to the transmitter, which is designed to determine the belt speed of the belt in the circumferential direction based on the first alternating reaction field and/or the second alternating reaction field. For this purpose, the transmitter can be designed as a magnetoresistive transmitter and/or include the function of a magnetoresistive sensor.

Wird der Riemen mit einer bestimmten Riemengeschwindigkeit in Umfangsrichtung angetrieben, und ist der Riemen in einem unbelasteten Zustand, so ist das zweite Markierungsteil in einem vorbestimmten Referenzabstand in Umfangsrichtung hinter dem ersten Markierungsteil angeordnet. Befindet sich der Riemen jedoch nicht in dem unbelasteten Zustand, sondern beispielsweise in einem belasteten Zustand, bei dem eine Zugkraft auf den Riemen, insbesondere auf ein Zugtrum des Riemens, wirkt, so vergrößert sich der Abstand zwischen dem zweiten Markierungsteil und dem ersten Markierungsteil in Umfangsrichtung. Hieraus resultiert, dass sich der Abstand zwischen der ersten Erfassungszeit und der zweiten Erfassungszeit bei der gleichen Riemengeschwindigkeit vergrößert, wenn der Riemen von dem unbelasteten Zustand in den zuvor erläuterten Belastungszustand wechselt. Daraus resultiert, dass aus der ersten und zweiten Erfassungszeit, der Riemengeschwindigkeit und dem Referenzabstand auf die Dehnung des Riemens in Umfangsrichtung, die auch als Längsdehnung des Riemens bezeichnet wird, geschlossen werden kann.If the belt is driven at a certain belt speed in the circumferential direction and the belt is in an unloaded state, the second marking part is arranged at a predetermined reference distance in the circumferential direction behind the first marking part. However, if the belt is not in the unloaded state, but rather, for example, in a loaded state in which a tensile force acts on the belt, in particular on a tension strand of the belt, the distance between the second marking part and the first marking part increases in the circumferential direction . As a result, the distance between the first detection time and the second detection time increases at the same belt speed when the belt changes from the unloaded state to the previously explained loaded state. The result of this is that the elongation of the belt in the circumferential direction, which is also referred to as the longitudinal elongation of the belt, can be deduced from the first and second detection times, the belt speed and the reference distance.

Deshalb ist die Auswerteeinheit dazu konfiguriert, eine Längsdehnung des Riemens basierend auf dem Referenzabstand, der Riemengeschwindigkeit, der ersten Erfassungszeit und der zweiten Erfassungszeit zu ermitteln.Therefore, the evaluation unit is configured to determine a longitudinal elongation of the belt based on the reference distance, the belt speed, the first detection time and the second detection time.

Zur Ermittlung der Längsdehnung des Riemens bedarf es deshalb keines mechanischen Eingriffs in den Riemen während des Betriebs des Riemens. Vielmehr kann die Längsdehnung des Riemens während des Betriebs des Riemens kontaktfrei erfasst werden. Darüber hinaus bieten das erste Markierungsteil und das zweite Markierungsteil, die jeweils in das Basismaterial des Riemens eingebettet sind, den Vorteil, dass die Ermittlung der Längsdehnung des Riemens auch bei einer hohen Temperatur des Riemens besonders präzise und/oder robust gegenüber Temperatureinflüssen möglich ist. Indem das erste und zweite Markierungsteil in das Basismaterial eingebettet sind, ist die Ermittlung der Längsdehnung des Riemens auch besonders robust gegenüber möglichen mechanischen Einflüssen, die auf den Riemen wirken können.To determine the longitudinal elongation of the belt, no mechanical intervention in the belt is required during operation of the belt. Rather, the longitudinal elongation of the belt can be recorded without contact during operation of the belt. In addition, the first marking part and the second marking part, which are each embedded in the base material of the belt, offer the advantage that the determination of the longitudinal elongation of the belt is possible in a particularly precise and/or robust manner against temperature influences, even at a high temperature of the belt. Because the first and second marking parts are embedded in the base material, the determination of the longitudinal elongation of the belt is also particularly robust against possible mechanical influences that can act on the belt.

Bei der Dehnung handelt es sich vorzugsweise um eine relative Dehnung. Die Längsdehnung des Riemens kann also eine relative Dehnung des Riemens in Längsrichtung sein.The elongation is preferably a relative elongation. The longitudinal stretch of the belt can therefore be a relative stretch of the belt in the longitudinal direction.

Wie zuvor erläutert, wird durch jedes der beiden ferromagnetischen Markierungsteile jeweils eine Veränderung des Referenzwechselfelds hervorgerufen. Die Veränderung findet aber nicht notwendigerweise gleichmäßig über das gesamte Frequenzband des Referenzwechselfelds statt. Es ist vielmehr möglich, dass jedes der beiden ferromagnetischen Markierungsteile zur Veränderung eines vorbestimmten Frequenzbereichs ausgebildet ist, so dass die dadurch hervorgerufene Veränderung des Referenzwechselfelds charakteristisch und/oder repräsentativ für das jeweilige Markierungsteil ist. Durch jedes Markierungsteil wird also vorzugsweise eine zugehörige Veränderung des Referenzwechselfelds hervorgerufen, so dass aus der Wechselwirkung des Referenzwechselfelds mit dem jeweiligen Markierungsteil ein entsprechendes Reaktionswechselfeld, nämlich das erste Reaktionswechselfeld oder das zweite Reaktionswechselfeld, entsteht. Das jeweilige Reaktionswechselfeld besteht jedoch zumindest nur für eine kurze Zeit, wenn das jeweilige Markierungsteil durch das Referenzwechselfeld hindurchgeführt wird. Jede Erfassungszeit kann auch als ein Erfassungszeitpunkt bezeichnet sein. Jede Erfassungszeit repräsentiert vorzugsweise den Zeitpunkt der maximalen Veränderung des jeweiligen Referenzwechselfelds durch das jeweilige Markierungsteil. Aus den beiden Erfassungszeiten ist ein Zeitraum ermittelbar, wobei aus dem Zeitraum, der Riemengeschwindigkeit und dem Referenzabstand auf die relative Dehnung des Riemens geschlossen werden kann. Hierzu ist die Auswerteeinheit bevorzugt entsprechend konfiguriert ausgebildet. Der Transmitter und die Auswerteeinheit können von einer gemeinsamen Einheit ausgebildet sein, die auch als Transmitter-Auswerteeinheit bezeichnet sein kann.As explained above, each of the two ferromagnetic marking parts causes a change in the alternating reference field. However, the change does not necessarily take place uniformly over the entire frequency band of the reference alternating field. Rather, it is possible for each of the two ferromagnetic marking parts to be designed to change a predetermined frequency range, so that the change in the alternating reference field caused thereby is characteristic and/or representative of the respective marking part. Each marking part therefore preferably causes an associated change in the alternating reference field, so that a corresponding alternating reaction field, namely the first alternating reaction field or the second alternating reaction field, arises from the interaction of the alternating reference field with the respective marking part. However, the respective alternating reaction field only exists for at least a short time when the respective marking part is passed through the alternating reference field. Each capture time may also be referred to as a capture time. Each detection time preferably represents the time of the maximum change in the respective reference alternating field respective marking part. A period of time can be determined from the two recording times, and the relative elongation of the belt can be deduced from the period, the belt speed and the reference distance. For this purpose, the evaluation unit is preferably configured accordingly. The transmitter and the evaluation unit can be formed by a common unit, which can also be referred to as a transmitter evaluation unit.

Eine vorteilhafte Ausgestaltung des Systems zeichnet sich dadurch aus, dass die Auswerteeinheit konfiguriert ist, basierend auf einer Historie ermittelter Längsdehnungen des Riemens eine Restlebensdauer des Riemens zu ermitteln. So kann die Auswerteeinheit ausgebildet sein, zeitlich hintereinander mehrere Längsdehnungen zu ermitteln. Die Ermittlung kann dabei in festen Abständen erfolgen. Es ist jedoch auch möglich, dass die Ermittlung getriggert durch die Erfassung des zweiten Reaktionswechselfelds erfolgt. Die erfassten Längsdehnungen können von der Auswerteeinheit gespeichert sein. Basierend auf diesen ermittelten Längsdehnungen kann die Auswerteeinheit deshalb dazu konfiguriert sein, die Restlebensdauer des Riemens zu ermitteln. Eine entsprechend ermittelte Restlebensdauer kann dazu dienen, die Wartungsintervalle und/oder den Austausch des Riemens vorausschauend zu planen.An advantageous embodiment of the system is characterized in that the evaluation unit is configured to determine a remaining service life of the belt based on a history of determined longitudinal stretches of the belt. The evaluation unit can thus be designed to determine several longitudinal strains one after the other. The determination can take place at fixed intervals. However, it is also possible for the determination to be triggered by the detection of the second reaction alternating field. The recorded longitudinal strains can be stored by the evaluation unit. Based on these determined longitudinal strains, the evaluation unit can therefore be configured to determine the remaining service life of the belt. A correspondingly determined remaining service life can be used to plan maintenance intervals and/or the replacement of the belt in advance.

Eine weitere vorteilhafte Ausgestaltung des Systems zeichnet sich dadurch aus, dass die erste Erfassungszeit einen Zeitpunkt einer maximalen Veränderung des Referenzwechselfelds durch das erste Markierungsteil repräsentiert, und dass die zweite Erfassungszeit einen Zeitpunkt einer maximalen Veränderung des Referenzwechselfelds durch das zweite Markierungsteil repräsentiert. Wird das erste bzw. das zweite Markierungsteil durch das Referenzwechselfeld bewegt, liegt die größte Veränderung des Referenzwechselfelds beispielsweise oftmals dann vor, wenn das jeweilige Markierungsteil mittig in dem Referenzwechselfeld angeordnet ist. Die Bewegung des jeweiligen Markierungsteils zu der mittigen Anordnung bzw. die Bewegung heraus aus dieser mittigen Anordnung führt jeweils zu einer Abnahme der Veränderung des Referenzwechselfelds. Um die erste Erfassungszeit möglichst präzise bestimmen zu können, ist es bevorzugt vorgesehen, dass die erste Erfassungszeit den Zeitpunkt der maximalen Veränderung des ersten Referenzwechselfelds durch das erste Markierungsteil repräsentiert. Entsprechendes gilt für die zweite Erfassungszeit, die durch den Zeitpunkt der maximalen Veränderung des Referenzwechselfelds durch das zweite Markierungsteil repräsentiert ist. Bei jedem Umlauf des Riemens können somit die Ersterfassungszeit und die Zweiterfassungszeit präzise bestimmt bzw. ermittelt werden.A further advantageous embodiment of the system is characterized in that the first detection time represents a time of a maximum change in the alternating reference field by the first marking part, and in that the second detection time represents a time of a maximum change in the alternating reference field by the second marking part. If the first or second marking part is moved through the alternating reference field, the greatest change in the alternating reference field often occurs, for example, when the respective marking part is arranged centrally in the alternating reference field. The movement of the respective marking part to the central arrangement or the movement out of this central arrangement leads to a decrease in the change in the reference alternating field. In order to be able to determine the first detection time as precisely as possible, it is preferably provided that the first detection time represents the time of the maximum change in the first alternating reference field by the first marking part. The same applies to the second Detection time, which is represented by the time of the maximum change in the reference alternating field by the second marking part. With each revolution of the belt, the first detection time and the second detection time can be precisely determined or determined.

Eine weitere vorteilhafte Ausgestaltung des Systems zeichnet sich dadurch aus, dass der Transmitter, insbesondere als ein Teil einer Transmitter-Auswerteeinheit, kontaktfrei an einem Trum des Riemens angeordnet ist. Der Trum kann dabei von einem Zugtrum des Riemens gebildet sein. Indem der Transmitter bzw. die Transmitterauswerteeinheit kontaktfrei zu dem Trum, insbesondere dem Zugtrum, des Riemens angeordnet ist, kann der Riemen reibungsfrei an dem Transmitter vorbei bewegt werden. Ein Verschleiß des Riemens und/oder des Transmitters bei der Verwendung des Transmitters und/oder der Auswerteeinheit zur Ermittlung der Längsdehnung des Riemens liegt deshalb nicht vor.A further advantageous embodiment of the system is characterized in that the transmitter, in particular as part of a transmitter evaluation unit, is arranged contact-free on a strand of the belt. The strand can be formed by a tension strand of the belt. By arranging the transmitter or the transmitter evaluation unit in contact-free manner with the strand, in particular the tension strand, of the belt, the belt can be moved past the transmitter without friction. There is therefore no wear on the belt and/or the transmitter when using the transmitter and/or the evaluation unit to determine the longitudinal elongation of the belt.

Eine weitere vorteilhafte Ausgestaltung des Systems zeichnet sich dadurch aus, dass der Transmitter, insbesondere als ein Teil der Transmitter-Auswerteeinheit, in einem Abstand zwischen 1 mm und 50 cm zu dem Trum des Riemens angeordnet ist. Hierbei handelt es sich vorzugsweise um ein Zugtrum des Riemens. Durch den vorbestimmten Abstand kann gewährleistet werden, dass der Transmitter keinen direkten mechanischen Kontakt zu dem Riemen aufweist. Somit kann die Längsdehnung des Riemens im laufenden Betrieb ohne negativen mechanischen Einfluss auf den Riemen ausgeführt werden. Indem der vorbestimmte Abstand zwischen 1 mm und 50 cm ist, kann darüber hinaus gewährleistet werden, dass elektromagnetische Störeinflüsse allenfalls einen vernachlässigbaren Einfluss auf die Erfassung des ersten und/oder zweiten Reaktionswechselfelds haben. Damit ist eine sehr störgrößenrobuste Erfassung des ersten bzw. zweiten Reaktionswechselfelds möglich.A further advantageous embodiment of the system is characterized in that the transmitter, in particular as part of the transmitter evaluation unit, is arranged at a distance of between 1 mm and 50 cm from the strand of the belt. This is preferably a tension strand of the belt. The predetermined distance can ensure that the transmitter has no direct mechanical contact with the belt. This means that the longitudinal stretching of the belt can be carried out during operation without any negative mechanical influence on the belt. Because the predetermined distance is between 1 mm and 50 cm, it can also be ensured that electromagnetic interference only has a negligible influence on the detection of the first and/or second alternating reaction field. This makes it possible to detect the first or second alternating reaction field in a very robust manner to disturbance variables.

Eine weitere vorteilhafte Ausgestaltung des Systems zeichnet sich dadurch aus, dass der Referenzabstand kleiner als eine kleinste Trumlänge des Riemens ist. Das zweite Markierungsteil ist in dem Referenzabstand in Umfangsrichtung des Riemens hinter dem ersten Markierungsteil angeordnet, wenn der Riemen in einem unbelasteten Zustand ist. Die kleinste Trumlänge des Riemens bezieht sich vorzugsweise auf die kleinste der mindestens einen Trumlänge des mindestens einen Zugtrums des Riemens. Es ist jedoch auch möglich, dass das System derart ausgestaltet ist, dass der Referenzabstand kleiner als eine Trumlänge eines beliebigen Zugtrums des Riemens ist. Somit ist der Referenzabstand derart bestimmt, dass beim Umlauf des Riemens zumindest ein Zeitpunkt besteht, bei dem sowohl das erste Markierungsteil als auch das zweite Markierungsteil in dem gleichen Zugtrum angeordnet sind. Durch die Zugbelastung kann der Abstand zwischen den beiden Markierunsgteilen größer als der Referenzabstand sein. Dies ist für gewöhnlich jedoch nur in einem einstelligen Prozentbereich der Fall. Deshalb kann weiterhin davon ausgegangen werden, dass auch bei einer Zugbelastung die Voraussetzung erfüllt ist, dass beide Markierungsteile beim Umlauf des Riemens an zumindestens einem Zeitpunkt zeitgleich in dem gleichen Zugtrum angeordnet sind. Dabei können die beiden Markierungsteile nacheinander durch das Referenzwechselfeld bewegt werden, was die zuvor erläuterte Ermittlung der Längsdehnung des Riemens ermöglicht. Die ermittelte Längsdehnung des Riemens repräsentiert dabei die Längsdehnung des Riemens im Zugtrum. Diese ist besonders interessant und/oder repräsentativ. Denn im Zugtrum findet oftmals die größte Belastung und/oder die größte Zugbelastung des Riemens statt. Diese Belastung bzw. die dort erfasste Längsdehnung des Riemens kann deshalb für die weitere Auswertung und/oder für weitere Voraussagen über den Zustand des Riemens vorteilhaft verwendet werden. Allerdings gibt es auch andere Fälle, in denen der Dehnungszustand eines Leertrums des Riemens von Interesse ist. In diesem Fall kann es vorgesehen sein, dass der Referenzabstand zwischen den Markierungspfeilen kleiner als eine Trumlänge eines Leertrums ist. Sodann können mittels des Systems beispielsweise die Längsdehnung des Leertrums, insbesondere aufgrund einer Vorspannung des Riemens, ermittelt werden. Auch dies kann in der Praxis von Interesse sein.A further advantageous embodiment of the system is characterized in that the reference distance is smaller than the smallest span length of the belt. The second marking part is arranged behind the first marking part at the reference distance in the circumferential direction of the belt when the belt is in an unloaded state. The smallest strand length of the belt preferably refers to the smallest of the at least one strand length of the at least one tension strand of the belt. However, it is also possible for the system to be designed in such a way that the reference distance is smaller than one is the strand length of any tension strand of the belt. The reference distance is therefore determined in such a way that during rotation of the belt there is at least one point in time at which both the first marking part and the second marking part are arranged in the same tension strand. Due to the tensile load, the distance between the two marking parts can be greater than the reference distance. However, this is usually only the case in a single-digit percentage range. Therefore, it can also be assumed that even in the event of a tensile load, the requirement is met that both marking parts are arranged simultaneously in the same tension strand at at least one point in time when the belt is rotating. The two marking parts can be moved one after the other through the reference alternating field, which enables the previously explained determination of the longitudinal elongation of the belt. The determined longitudinal elongation of the belt represents the longitudinal elongation of the belt in the tension strand. This is particularly interesting and/or representative. The tension strand is often where the greatest load and/or the greatest tensile load on the belt occurs. This load or the longitudinal stretch of the belt recorded there can therefore be advantageously used for further evaluation and/or for further predictions about the condition of the belt. However, there are also other cases in which the stretch state of a slack strand of the belt is of interest. In this case, it can be provided that the reference distance between the marking arrows is smaller than a span length of an empty span. The system can then be used to determine, for example, the longitudinal elongation of the slack strand, in particular due to a pretension of the belt. This can also be of interest in practice.

Eine weitere vorteilhafte Ausgestaltung des Systems zeichnet sich dadurch aus, dass der Referenzabstand maximal 90 %, maximal 80 %, maximal 70 %, maximal 60 % oder maximal 50 % einer Trumlänge des Riemens beträgt. Hierbei handelt es sich vorzugsweise um die kürzeste Trumlänge und/oder um die Trumlänge des Zugtrums, insbesondere des kürzesten Zugtrums. Durch die Begrenzung des Referenzabstands kann besonders einfach sichergestellt werden, dass die beiden Markierungsteile beim Umlauf des Riemens gleichzeitig in dem entsprechenden Trum mit der Trumlänge angeordnet sind, um die Erfassung des ersten und zweiten Reaktionswechselfelds an dem entsprechenden Trum zu gewährleisten.A further advantageous embodiment of the system is characterized in that the reference distance is a maximum of 90%, a maximum of 80%, a maximum of 70%, a maximum of 60% or a maximum of 50% of a span length of the belt. This is preferably the shortest strand length and/or the strand length of the tension strand, in particular the shortest tension strand. By limiting the reference distance, it is particularly easy to ensure that the two marking parts are arranged simultaneously in the corresponding strand with the strand length when the belt rotates, in order to ensure the detection of the first and second alternating reaction fields on the corresponding strand.

Eine weitere vorteilhafte Ausgestaltung des Systems zeichnet sich dadurch aus, dass jedes Markierungsteil passiv, insbesondere rein passiv, ausgebildet ist. Jedes der beiden Markierungsteile kann somit als ein passives, ferromagnetisches Markierungsteil ausgebildet sein. Die passive Ausgestaltung des jeweiligen Markierungsteils ist zur Veränderung des Referenzwechselfelds ausreichend, da das ferromagnetische Material des jeweiligen Markierungsteils durch die Anordnung in dem Referenzwechselfeld eine durch Induktion basierte Veränderung des Wechselfelds hervorrufen kann. Keines der beiden Markierungsteile ist deshalb mit weiteren elektronischen Bauteilen gekoppelt. Vielmehr ist es bevorzugt vorgesehen, dass jedes der beiden Markierungsteile vollständig in das Basismaterial des Riemens eingebettet ist, so dass jedes der beiden Markierungsteile vollständig von dem Basismaterial umhüllt ist. Dadurch kann gewährleistet werden, dass jedes der beiden Markierungsteile kontaktfrei zu dem Festigkeitsträger des Riemens und/oder anderen möglichen Bauteilen des Riemens angeordnet ist. Dies bietet wiederum den Vorteil, dass auch bei einer größeren Belastung des Riemens kein Reibeffekt zwischen dem Festigkeitsträger des Riemens und einem der beiden Markierungsteile auftritt. Somit kann effektiv gewährleistet werden, dass keine Reibung und/oder kein Verschleiß des Riemens durch die Einbettung der Markierungsteile in das Basismaterial des Riemens hervorgerufen wird. Der Riemen ist deshalb besonders robust.A further advantageous embodiment of the system is characterized in that each marking part is designed to be passive, in particular purely passive. Each of the two marking parts can therefore be designed as a passive, ferromagnetic marking part. The passive design of the respective marking part is sufficient to change the reference alternating field, since the ferromagnetic material of the respective marking part can cause an induction-based change in the alternating field due to the arrangement in the reference alternating field. Neither of the two marking parts is therefore coupled to other electronic components. Rather, it is preferably provided that each of the two marking parts is completely embedded in the base material of the belt, so that each of the two marking parts is completely covered by the base material. This can ensure that each of the two marking parts is arranged without contact with the strength member of the belt and/or other possible components of the belt. This in turn offers the advantage that no friction effect occurs between the strength member of the belt and one of the two marking parts, even when the belt is under greater load. This can effectively ensure that no friction and/or wear of the belt is caused by embedding the marking parts in the base material of the belt. The belt is therefore particularly robust.

Eine weitere vorteilhafte Ausgestaltung des Systems zeichnet sich dadurch aus, dass jedes Markierungsteil als ein stabförmiges Markierungsteil oder als ein folienförmiges Markierungsteil ausgebildet ist. Außerdem ist es bevorzugt vorgesehen, dass sich jedes Markierungsteil mit seiner größten Ausdehnung quer zur Umfangsrichtung des Riemens erstreckt. So kann beispielsweise die Längsachse eines jeden stabförmigen Markierungsteils quer zur Umfangsrichtung angeordnet sein. Bei einem folienförmigen Markierungsteil besteht auch die Möglichkeit, dass die Folie eine größte Ausdehnung in eine Richtung aufweist, die quer zur Umfangsrichtung angeordnet ist. Außerdem ist es bevorzugt vorgesehen, dass sich jedes Markierungsteil von einer Seitenwand zu der gegenüberliegenden Seitenwand des Riemens erstreckt. Jede Seitenwand kann an einer entsprechenden Seitenflanke des Riemens angeordnet sein. Somit kann sich jedes Markierungsteil zumindest im Wesentlichen vollständig in Querrichtung von der einen Seitenwand zu der gegenüberliegenden Seitenwand erstrecken. Es ist jedoch auch möglich, dass eine Erstreckungslänge eines jeden Markierungsteils zwischen 95 % und 70 % des Abstands zwischen den beiden Seitenwänden beträgt. Damit kann effektiv gewährleistet werden, dass jedes Markierungsteil zumindest durch einen kleinen Abstand von der jeweiligen Außenseite nach innen versetzt beabstandet ist. Dadurch kann eine elektromagnetische Beeinflussung der Markierungsteile verhindert und/oder eine Isolierung der Markierungsteile durch das Basismaterial besonders effektiv sichergestellt werden. Jedes Markierungsteil kann beispielsweise einen Durchmesser und/oder eine Stärke von 5 µm bis 0,5 mm aufweisen. Dadurch wird die Steifigkeit des Riemens vernachlässigbar gering beeinflusst.A further advantageous embodiment of the system is characterized in that each marking part is designed as a rod-shaped marking part or as a film-shaped marking part. In addition, it is preferably provided that each marking part extends with its greatest extent transversely to the circumferential direction of the belt. For example, the longitudinal axis of each rod-shaped marking part can be arranged transversely to the circumferential direction. With a film-shaped marking part, there is also the possibility that the film has a greatest extent in a direction that is arranged transversely to the circumferential direction. In addition, it is preferably provided that each marking part extends from one side wall to the opposite side wall of the belt. Each sidewall may be located on a corresponding side flank of the belt. Thus, each marking part can extend at least substantially completely in the transverse direction from one side wall to the opposite side wall. However, it is also possible that an extension length of each Marking part is between 95% and 70% of the distance between the two side walls. This can effectively ensure that each marking part is spaced at least a small distance inwards from the respective outside. As a result, electromagnetic influence on the marking parts can be prevented and/or insulation of the marking parts can be ensured particularly effectively by the base material. Each marking part can, for example, have a diameter and/or a thickness of 5 μm to 0.5 mm. This has a negligible influence on the stiffness of the belt.

Eine vorteilhafte Ausgestaltung des Systems zeichnet sich dadurch aus, dass jedes Markierungsteil vorgefertigt ist. Ein entsprechend vorgefertigtes Markierungsteil kann somit bei der Herstellung des Riemens besonders einfach in das Basismaterial des Riemens eingebettet werden.An advantageous embodiment of the system is characterized by the fact that each marking part is prefabricated. A correspondingly prefabricated marking part can therefore be embedded particularly easily into the base material of the belt when producing the belt.

Eine nicht beanspruchte Ausgestaltung des Systems zeichnet sich dadurch aus, dass jedes Markierungsteil als gedrucktes Markierungsteil ausgebildet ist. Dabei kann das Markierungsteil durch ein gedrucktes, ferromagnetisches Metall-Markierungsteil gebildet sein. Es ist aber auch möglich, dass das Markierungsteil durch eine Materialmischung aus ferromagnetischem Material und einem weiteren druckfähigen Material gebildet ist. Bei der Herstellung des Riemens kann jedes Markierungsteil dabei an eine vorgesehene Stelle gedruckt werden, um daraufhin das jeweilige Markierungsteil vollständig in das Gummimaterial einzubetten. Dadurch ist eine besonders einfache und zugleich präzise Einbettung des jeweiligen Markierungsteils in das Gummimaterial möglich.An unclaimed embodiment of the system is characterized in that each marking part is designed as a printed marking part. The marking part can be formed by a printed, ferromagnetic metal marking part. However, it is also possible for the marking part to be formed by a material mixture of ferromagnetic material and another printable material. When producing the belt, each marking part can be printed at a designated location in order to then completely embed the respective marking part into the rubber material. This makes it possible to embed the respective marking part in the rubber material in a particularly simple and at the same time precise manner.

Eine weitere vorteilhafte Ausgestaltung des Systems zeichnet sich dadurch aus, dass jedes Markierungsteil einstückig ausgebildet ist. Dadurch ist es möglich, dass jedes Markierungsteil vollständig von dem Basismaterial im Riemen umgeben eingebettet ist. Durch das Basismaterial kann jedes Markierungsteil somit getrennt zu den weiteren, möglichen Bauteilen im Riemen angeordnet und/oder elektrisch isoliert zu dem restlichen Riemen ausgebildet sein. Die beiden Markierungsteile können durch ihre einstückig Ausgestaltung getrennt, und zwar vorzugsweise in dem Referenzabstand zueinander, angeordnet sein.A further advantageous embodiment of the system is characterized in that each marking part is formed in one piece. This makes it possible for each marking part to be completely embedded in the belt, surrounded by the base material. Due to the base material, each marking part can thus be arranged separately from the other possible components in the belt and/or designed to be electrically insulated from the remaining belt. The two marking parts can be arranged separately due to their one-piece design, preferably at the reference distance from one another.

Eine erfindungsgemäße Ausgestaltung des Systems zeichnet sich dadurch aus, dass das erste Markierungsteil und das zweite Markierungsteil zumindest indirekt miteinander verbunden ausgebildet sind. Zwischen dem ersten und dem zweiten Markierungsteil können sich dabei Verbindungsstege, beispielsweise in Umfangsrichtung, erstrecken. Durch diese Verbindungsstege können das erste und zweite Markierungsteil eine mechanisch feste Verbindung zueinander aufweisen. Die Verbindungsstege sind vorzugsweise elektrisch isolierend ausgebildet. Das erste und zweite Markierungsteil sowie die Verbindungsstege können in Form eines rechteckigen Rahmens angeordnet sein. Dadurch kann der Referenzabstand zwischen den beiden Markierungsteilen in Umfangsrichtung besonders sicher gewährleistet werden. So kann der entsprechende Rahmen mit dem ersten und zweiten Markierungsteil sowie den Verbindungsstegen in das Basismaterial eingebettet werden, um daraufhin das Basismaterial beispielsweise zu vulkanisieren. Durch die Verbindungsstege kann der Referenzabstand aufrechterhalten werden. Der Referenzabstand zwischen dem ersten und zweiten Markierungsteil in unbelastetem Zustand des Riemens kann also besonders sicher gewährleistet werden. Die Verbindungsstege können elektrisch isolierend oder elektrisch leitend ausgebildet sein. Auch bei einer elektrisch leitenden Ausgestaltung der Verbindungsstege wurde in der Praxis festgestellt, dass jedes der beiden Markierungsteile eine jeweils erkennbare, zugehörige Veränderung des Referenzmagnetfelds hervorruft, was zu dem ersten bzw. zweiten Reaktionswechselfeld führt. Es ist deshalb auch möglich, dass das erste und zweite Markierungsteil sowie die beiden Verbindungsstege als verbundener und/oder einstückiger Rahmen ausgebildet sind.An embodiment of the system according to the invention is characterized in that the first marking part and the second marking part are designed to be at least indirectly connected to one another. Connecting webs can extend between the first and second marking parts, for example in the circumferential direction. Through these connecting webs, the first and second marking parts can have a mechanically fixed connection to one another. The connecting webs are preferably designed to be electrically insulating. The first and second marking parts as well as the connecting webs can be arranged in the form of a rectangular frame. As a result, the reference distance between the two marking parts in the circumferential direction can be ensured particularly reliably. The corresponding frame with the first and second marking parts as well as the connecting webs can be embedded in the base material in order to then vulcanize the base material, for example. The reference distance can be maintained through the connecting webs. The reference distance between the first and second marking parts when the belt is in an unloaded state can therefore be guaranteed particularly reliably. The connecting webs can be designed to be electrically insulating or electrically conductive. Even with an electrically conductive design of the connecting webs, it has been found in practice that each of the two marking parts causes a recognizable, associated change in the reference magnetic field, which leads to the first or second alternating reaction field. It is therefore also possible for the first and second marking parts as well as the two connecting webs to be designed as a connected and/or one-piece frame.

Weitere Merkmale, Vorteile und Anwendungsmöglichkeiten der vorliegenden Erfindung ergeben sich aus der nachfolgenden Beschreibung der Ausführungsbeispiele und den Figuren. Dabei bilden alle beschriebenen und/oder bildlich dargestellten Merkmale für sich und in beliebiger Kombination den Gegenstand der Erfindung auch unabhängig von ihrer Zusammensetzung in den einzelnen Ansprüchen oder deren Rückbezügen. In den Figuren stehen weiterhin gleiche Bezugszeichen für gleiche oder ähnliche Objekte.

Figur 1
zeigt eine vorteilhafte Ausgestaltung des Systems in einer schematischen Ansicht
Figur 2
zeigt einen Abschnitt eines Riemens in einer schematischen Ansicht
Figur 3 bis 5
zeigen Frequenzgänge von Wechselfeldern in beispielhaften Ausgestaltungen.
Figur 6
zeigt eine beispielhafte Ausgestaltung eines zeitlichen Verlaufs einer mittleren Feldstärke.
Figur 7
zeigt eine weitere vorteilhafte Ausgestaltung eines Abschnitts eines Riemens in einer schematischen Ansicht.
Further features, advantages and possible applications of the present invention result from the following description of the exemplary embodiments and the figures. All described and/or illustrated features individually and in any combination form the subject matter of the invention, regardless of their composition in the individual claims or their references. In the figures, the same reference numbers continue to stand for the same or similar objects.
Figure 1
shows an advantageous embodiment of the system in a schematic view
Figure 2
shows a section of a belt in a schematic view
Figures 3 to 5
show frequency responses of alternating fields in exemplary configurations.
Figure 6
shows an exemplary embodiment of a time course of an average field strength.
Figure 7
shows a further advantageous embodiment of a section of a belt in a schematic view.

In der Figur 1 ist eine vorteilhafte Ausgestaltung des Systems 2 schematisch dargestellt. Das Systems 2 weist einen Riemen 4 und eine Antriebsvorrichtung 6 mit beispielsweise zwei Riemenscheiben 8, 10 auf. Eine der beiden Riemenscheiben 8, 10 kann als antreibende Riemenscheibe mit einem Motor der Antriebsvorrichtung gekoppelt sein. Der Riemen 4 ist in Umfangsrichtung U ringförmig umlaufend ausgebildet und umschlingt jede der beiden Riemenscheiben 8, 10 teilweise. Der Riemen 4 kann deshalb von der Antriebsvorrichtung 6 mit den beiden Riemenscheiben 8, 10 angetrieben werden, und zwar sodass der Riemen 4 in Umfangsrichtung U umläuft.In the Figure 1 an advantageous embodiment of the system 2 is shown schematically. The system 2 has a belt 4 and a drive device 6 with, for example, two pulleys 8, 10. One of the two pulleys 8, 10 can be coupled as a driving pulley to a motor of the drive device. The belt 4 is designed to be annular in the circumferential direction U and partially wraps around each of the two pulleys 8, 10. The belt 4 can therefore be driven by the drive device 6 with the two pulleys 8, 10, so that the belt 4 rotates in the circumferential direction U.

Der Riemen 4 weist ein Basismaterial 16 und mindestens einen Festigkeitsträger 18 auf. Rein beispielhaft wird im Folgenden davon ausgegangen, dass der Riemen 4 einen Festigkeitsträger 18 aufweist. Das Basismaterial 16 kann beispielsweise teilweise oder vollständig von Gummimaterial oder teilweise oder vollständig von Polyurethanmaterial gebildet sein. Andere Materialien für das Basismaterial 16 können jedoch auch vorgesehen sein. Vorzugsweise ist das Basismaterial 16 elektrisch isolierend ausgebildet. Der Festigkeitsträger 18 ist als ein durchgängiger in Umfangsrichtung U schraubenförmig gewendelter Cord 24 in das Basismaterial 16 eingebettet. Der Festigkeitsträger 18 dient zur Übertragung von Kräften in Umfangsrichtung U des Riemens 4. Der Festigkeitsträger 18 kann beispielsweise von einem metallischen Draht oder von einem Kunststofffilamentstrang, wie beispielsweise einem Kunststofffaserstrang aus Polyamid gebildet sein. Rein beispielhaft wird in diesem Zusammenhang auf den Abschnitt des Riemens 4 aus der Figur 2 verwiesen. Aus der Figur 2 geht beispielhaft hervor, dass die einzelnen Windungen des den Festigkeitsträger 18 bildenden Cords 24 in Querrichtung Q des Riemens 4 verteilt zueinander angeordnet sein können. Jeder der Windungen erstreckt sich dabei in Umfangsrichtung U.The belt 4 has a base material 16 and at least one reinforcement 18. Purely by way of example, it is assumed below that the belt 4 has a strength member 18. The base material 16 can, for example, be formed partially or completely from rubber material or partially or completely from polyurethane material. However, other materials for the base material 16 may also be provided. The base material 16 is preferably designed to be electrically insulating. The reinforcement 18 is embedded in the base material 16 as a continuous cord 24 that is wound helically in the circumferential direction U. The strength member 18 serves to transmit forces in the circumferential direction U of the belt 4. The strength member 18 can be formed, for example, from a metallic wire or from a plastic filament strand, such as a plastic fiber strand made of polyamide. In this context, purely as an example, reference is made to the section of the belt 4 from the Figure 2 referred. From the Figure 2 As an example, the individual turns of the cord 24 forming the reinforcement 18 can be arranged distributed relative to one another in the transverse direction Q of the belt 4. Each of the turns extends in the circumferential direction U.

Der Riemen 4 weist außerdem ein erstes ferromagnetisches Markierungsteil 20 sowie ein zweites ferromagnetisches Markierungsteil 22 auf. Das erste ferromagnetische Markierungsteil 20 wird auch kurz als erstes Markierungsteil 20 bezeichnet. Das zweite ferromagnetische Markierungsteil 22 wird auch kurz als zweites Markierungsteil 22 bezeichnet. Das erste Markierungsteil 20 und das zweite Markierungsteil 22 sind jeweils in das Basismaterial 16 des Riemens 4 eingebettet. Dabei können die beiden Markierungsteile 20, 22 oberhalb des Festigkeitsträgers 18 in das Basismaterial 16 eingebettet sein. Grundsätzlich ist es aber auch möglich, dass die beiden Markierungsteile 20, 22 unterhalb des Festigkeitsträgers 18 in das Basismaterial 16 eingebettet ist. Darüber hinaus besteht die Möglichkeit, dass die beiden Markierungsteile 20, 22 auf einer Außenseite 44 des Riemens 4 angeordnet sind. Diese Ausgestaltung ist in der Figur 2 nicht dargestellt. Bei der Außenseite 44 kann es sich beispielsweise um den sogenannten Rücken des Riemens 4 handeln.The belt 4 also has a first ferromagnetic marking part 20 and a second ferromagnetic marking part 22. The first ferromagnetic marking part 20 is also briefly referred to as the first marking part 20. The second ferromagnetic marking part 22 is also briefly referred to as the second marking part 22. The first marking part 20 and the second marking part 22 are each embedded in the base material 16 of the belt 4. The two marking parts 20, 22 can be embedded in the base material 16 above the reinforcement 18. In principle, it is also possible for the two marking parts 20, 22 to be embedded in the base material 16 below the reinforcement 18. In addition, there is the possibility that the two marking parts 20, 22 are arranged on an outside 44 of the belt 4. This design is in the Figure 2 not shown. The outside 44 can be, for example, the so-called back of the belt 4.

Jeder der beiden ferromagnetischen Markierungsteile 20, 22 kann vollständig oder zumindest teilweise von ferromagnetischen Material und/oder Stoff gebildet sein. Beispielsweise sind Eisen, Nickel oder Kobalt Stoffe mit ferromagnetischen Eigenschaften. In der Praxis werden jedoch häufig Legierungen mit ferromagnetischen Eigenschaften verwendet. Entsprechende Legierungen können beispielsweise ALNiCo-, SmCo- oder NiFeCo-Legierungen sein. Bei jedem der beiden Markierungsteile 20, 22 kann es sich deshalb beispielsweise um ein ferromagnetisches Metallmarkierungsteil oder um ein ferromagnetisches Legierungsmetallmarkierungsteil handeln.Each of the two ferromagnetic marking parts 20, 22 can be formed completely or at least partially from ferromagnetic material and/or substance. For example, iron, nickel or cobalt are substances with ferromagnetic properties. However, in practice, alloys with ferromagnetic properties are often used. Corresponding alloys can be, for example, ALNiCo, SmCo or NiFeCo alloys. Each of the two marking parts 20, 22 can therefore be, for example, a ferromagnetic metal marking part or a ferromagnetic alloy metal marking part.

In einem unbelasteten Zustand des Riemens 4, wenn also keine Zugkraft in Umfangsrichtung auf den Riemen 4 wirkt, ist das zweite Markierungsteil 22 in einem vorbestimmten Referenzabstand R in Umfangsrichtung U hinter dem ersten Markierungsteil 20 angeordnet. Hierbei handelt es sich vorzugsweise um den mittleren Abstand zwischen den beiden Markierungsteilen 20, 22 in dem unbelasteten Zustand des Riemens 4.In an unloaded state of the belt 4, i.e. when no tensile force acts on the belt 4 in the circumferential direction, the second marking part 22 is arranged at a predetermined reference distance R in the circumferential direction U behind the first marking part 20. This is preferably the average distance between the two marking parts 20, 22 in the unloaded state of the belt 4.

Wie aus der Figur 2 beispielhaft hervorgeht, ist es bevorzugt vorgesehen, dass jede der beiden Markierungsteile 20, 22 als ein stabförmiges Markierungsteil 20, 22 ausgebildet ist. Jedes der beiden Markierungsteile 20, 22 kann sich also in Querrichtung Q von einer ersten Seitenwand 46 des Riemens 4 zu einer gegenüberliegenden Seitenwand 48 des Riemens 4 erstrecken. Bevorzugt ist es jedoch vorgesehen, dass jeder der beiden Markierungsteile 20, 22 kürzer als der Abstand in Querrichtung zwischen den beiden Seitenwänden 46, 48 ist. Dadurch kann gewährleistet werden, dass jeder der beiden Markierungsteile 20, 22 vollständig in das Basismaterial 16 des Riemens 4 eingebettet ist.Like from the Figure 2 As can be seen by way of example, it is preferably provided that each of the two marking parts 20, 22 is designed as a rod-shaped marking part 20, 22. Each of the two marking parts 20, 22 can therefore extend in the transverse direction Q from a first side wall 46 of the belt 4 to an opposite side wall 48 of the belt 4. However, it is preferably provided that each of the two marking parts 20, 22 is shorter than the distance in the transverse direction between the two side walls 46, 48. This can ensure that each of the two marking parts 20, 22 is completely embedded in the base material 16 of the belt 4.

Außerdem ist es bevorzugt vorgesehen, dass das zweite Markierungsteil 22 parallel zu dem ersten Markierungsteil 20 angeordnet ist. Dadurch kann ein konstanter Referenzabstand R zwischen den beiden Markierungsteilen 20, 22 gewährleistet werden. Der Referenzabstand R zwischen den beiden Markierungsteilen 20, 22 liegt jedoch vorzugsweise nur im unbelasteten Zustand des Riemens vor. Im Betrieb des Riemens 4 wirken auf den Riemen 4 Zugkräfte in Umfangsrichtung U, was eine Dehnung des Riemens 4 in Umfangsrichtung U hervorruft. Dadurch vergrößert sich der Abstand zwischen dem ersten Markierungsteil 20 und dem zweiten Markierungsteil 22 auf einen Messabstand M, der größer als der Referenzabstand R ist. Der Quotient aus dem Messabstand M und dem Referenzabstand Rist dabei repräsentativ für die Längsdehnung des Riemens. Denn die Längsdehnung des Riemens ist eine relative Dehnung des Riemens 4. Vorzugsweise ist die Längsdehnung des Riemens durch das Verhältnis von dem Messabstand M zu dem Referenzabstand R bestimmt. Insbesondere wenn das erste und zweite Markierungsteil 20 in dem Basismaterial 16 des Riemens 4 eingebettet sind, ist eine Erfassung der beiden Markierungsteile 20, 22 nur indirekt möglich.In addition, it is preferably provided that the second marking part 22 is arranged parallel to the first marking part 20. This makes it possible to ensure a constant reference distance R between the two marking parts 20, 22. However, the reference distance R between the two marking parts 20, 22 is preferably only present in the unloaded state of the belt. During operation of the belt 4, tensile forces act on the belt 4 in the circumferential direction U, which causes the belt 4 to stretch in the circumferential direction U. This increases the distance between the first marking part 20 and the second marking part 22 to a measuring distance M that is larger than the reference distance R. The quotient of the measuring distance M and the reference distance R is representative of the longitudinal elongation of the belt. This is because the longitudinal elongation of the belt is a relative elongation of the belt 4. The longitudinal elongation of the belt is preferably determined by the ratio of the measuring distance M to the reference distance R. In particular, if the first and second marking parts 20 are embedded in the base material 16 of the belt 4, detection of the two marking parts 20, 22 is only possible indirectly.

Das System weist deshalb einen Transmitter 12 und eine Auswerteeinheit 14 auf. Der Transmitter 12 und die Auswerteeinheit 14 können kombiniert ausgebildet sein und/oder einer gemeinsamen Vorrichtung 50 zugeordnet sein. Die Vorrichtung 50 kann somit den Transmitter 12 und die Auswerteeinheit 14 aufweisen und/oder ausbilden.The system therefore has a transmitter 12 and an evaluation unit 14. The transmitter 12 and the evaluation unit 14 can be combined and/or assigned to a common device 50. The device 50 can thus have and/or form the transmitter 12 and the evaluation unit 14.

Der Transmitter 12 ist in einem vorbestimmten Abstand A von dem Riemen 4 beabstandet angeordnet. So kann der Transmitter 12 beispielweise in einem Abstand A zwischen 1 mm und 50 cm zu einem Zugtrum 52 des Riemens 4 angeordnet sein. Dabei kann der Transmitter 12 den Rücken bzw. der Außenseite 44 des Riemens 4 zugewandt sein. Durch den zuvor genannten, vorbestimmten Abstand A wird besonders einfach gewährleistet, dass der Transmitter 12 kontaktfrei an dem Trum 32, insbesondere dem Zugtrum 52, des Riemens 4 angeordnet ist.The transmitter 12 is arranged at a predetermined distance A from the belt 4. For example, the transmitter 12 can be arranged at a distance A between 1 mm and 50 cm from a tension strand 52 of the belt 4. The transmitter 12 can face the back or the outside 44 of the belt 4. The previously mentioned, predetermined distance A ensures particularly easily that the transmitter 12 is arranged contact-free on the strand 32, in particular the tension strand 52, of the belt 4.

Der Transmitter 12 ist zum Erzeugen eines ersten, elektromagnetischen Wechselfelds, das als das Referenzwechselfeld 26 bezeichnet wird, ausgebildet. Das Referenzwechselfeld 26 ist in Figur 1 schematisch durch Magnetfeldlinien angedeutet. Das Referenzwechselfeld 26 durchdringt den Riemen 4. Der Riemen 4 ist von der Antriebsvorrichtung 6 angetrieben. Dadurch wird gewährleistet, dass das erste Markierungsteil 20 und das zweite Markierungsteil 22 nacheinander in Umfangsrichtung U durch das Referenzwechselfeld 26 bewegt werden.The transmitter 12 is designed to generate a first alternating electromagnetic field, which is referred to as the reference alternating field 26. The reference alternating field 26 is in Figure 1 indicated schematically by magnetic field lines. The alternating reference field 26 penetrates the belt 4. The belt 4 is driven by the drive device 6. This ensures that the first marking part 20 and the second marking part 22 are moved one after the other in the circumferential direction U through the reference alternating field 26.

In der Figur 3 ist die Magnetfeldstärke Y in Abhängigkeit der Frequenz f des Referenzmagnetfelds 26 beispielhaft und schematisch dargestellt. Der entsprechend dargestellte Frequenzgang soll nicht einschränkend verstanden werden.In the Figure 3 the magnetic field strength Y is shown as an example and schematically as a function of the frequency f of the reference magnetic field 26. The frequency response shown is not intended to be limiting.

Das erste ferromagnetische Markierungsteil 20 ist zur Veränderung des Referenzwechselfelds 26 in das erste Reaktionswechselfeld ausgebildet, wenn das Reaktionswechselfeld auf das erste ferromagnetische Markierungsteil 20, oder umgekehrt, einwirkt. Durch die Wechselwirkung zwischen dem Referenzwechselfeld 26 und dem ersten Markierungsteil 20 entsteht also aus dem Referenzwechselfeld das erste Reaktionswechselfeld. Dies weist eine Veränderung gegenüber dem ursprünglichen Referenzwechselfeld 26 auf.The first ferromagnetic marking part 20 is designed to change the reference alternating field 26 into the first alternating reaction field when the alternating reaction field acts on the first ferromagnetic marking part 20, or vice versa. The interaction between the alternating reference field 26 and the first marking part 20 creates the first alternating reaction field from the alternating reference field. This represents a change compared to the original alternating reference field 26.

Wie zuvor erläutert, werden das erste Markierungsteil 20 und das zweite Markierungsteil 22 nacheinander an dem Transmitter 12 vorbeigeführt, so dass zunächst das erste Markierungsteil 20 durch die Wechselwirkung mit dem Referenzwechselfeld 26 das erste Reaktionswechselfeld hervorruft. Der Transmitter 12 ist zur Erfassung des ersten Reaktionswechselfelds und einer zugehörigen ersten Erfassungszeit T1 ausgebildet, wenn das erste Markierungsteil 20 an dem Transmitter 12 vorbeigeführt wird.As explained above, the first marking part 20 and the second marking part 22 are guided past the transmitter 12 one after the other, so that initially the first marking part 20 causes the first alternating reaction field through the interaction with the reference alternating field 26. The transmitter 12 is designed to detect the first alternating reaction field and an associated first detection time T1 when the first marking part 20 is guided past the transmitter 12.

In der Figur 6 ist beispielhaft die mittlere Feldstärke H des Wechselfelds im Bereich zwischen dem Riemen 4 und dem Transmitter 12 schematisch dargestellt. Sofern ein Riemenbereich ohne eines der beiden Markierungsteile durch das Referenzwechselfeld 26 bewegt wird, liegt zumindest im Wesentlichen keine Änderung der mittleren Feldstärke H vor. Wird hingegen das erste Markierungsteil 20 mit dem Riemen 4 durch das Referenzwechselfeld 26 geführt, verändert sich die mittlere Feldstärke H im Bereich 28, was als erste Veränderung der Feldstärke H bezeichnet wird. Nachdem das erste Markierungsteil 20 an dem Transmitter 12 vorbeigeführt ist, nimmt die mittlere Feldstärke H wieder den vorherigen Wert zumindest im Wesentlichen an.In the Figure 6 For example, the average field strength H of the alternating field in the area between the belt 4 and the transmitter 12 is shown schematically. If a belt area without one of the two marking parts is moved through the reference alternating field 26, there is at least essentially no change in the average field strength H. However, if the first marking part 20 with the belt 4 is guided through the reference alternating field 26, the average field strength H changes in the area 28, which is referred to as the first change in the field strength H. After the first marking part 20 is guided past the transmitter 12, the average field strength H again at least essentially assumes the previous value.

Das zweite ferromagnetische Markierungsteil 22 ist zur Veränderung des Referenzwechselfelds 26 in das zweite Reaktionswechselfeld ausgebildet, wenn das Referenzwechselfeld 26 auf das zweite Markierungsteil 22, oder umgekehrt, einwirkt. Durch die Wechselwirkung zwischen dem Referenzwechselfeld 26 und dem zweiten Markierungsteil 22 entsteht also aus dem Referenzwechselfeld das erste Reaktionswechselfeld 26. Dies weist eine Veränderung gegenüber dem Referenzwechselfeld 26 auf. Eine entsprechende Veränderung im Bereich 30 in der Figur 6 zeigt deshalb ebenfalls die entsprechende Änderung der mittleren Feldstärke H an. Diese ist durch die Bewegung des zweiten Markierungsteils 22 durch das Referenzwechselfelds 26 verursacht.The second ferromagnetic marking part 22 is designed to change the alternating reference field 26 into the second alternating reaction field when the alternating reference field 26 acts on the second marking part 22, or vice versa. The interaction between the alternating reference field 26 and the second marking part 22 creates the first alternating reaction field 26 from the alternating reference field. This represents a change compared to the alternating reference field 26. A corresponding change in the area 30 in the Figure 6 therefore also shows the corresponding change in the average field strength H. This is caused by the movement of the second marking part 22 through the alternating reference field 26.

In der Figur 4 ist das Spektrum des Wechselfelds dargestellt, das zum Zeitpunkt T1 in dem Bereich zwischen dem Riemen 4 und dem Transmitter 12 anliegt, wobei die Feldstärke Z1 in Abhängigkeit der Frequenz aufgetragen ist. Auch hier ist im Vergleich zu dem Frequenzgang aus Figur 3 eine Veränderung 34 zu erkennen, die zu der Veränderung 28 in Figur 6 korrespondiert.In the Figure 4 The spectrum of the alternating field is shown which is present at time T1 in the area between the belt 4 and the transmitter 12, the field strength Z1 being plotted as a function of the frequency. Here too, the frequency response is off in comparison Figure 3 to recognize a change 34 that corresponds to the change 28 in Figure 6.

In der Figur 5 ist die Feldstärke Z2 für den Bereich zwischen dem Riemen 4 und dem Transmitter 12 gegenüber der Frequenz f ausgetragen. Auch dieses entsprechende Spektrum zeigt eine Veränderung 36 gegenüber dem Spektrum aus der Figur 3 auf, wobei die Veränderung 36 zu der Veränderung 30 aus der Figur 6 korrespondiert.In the Figure 5 the field strength Z2 for the area between the belt 4 and the transmitter 12 is plotted against the frequency f. This corresponding spectrum also shows a change 36 compared to the spectrum from the Figure 3 on, with the change 36 being the change 30 from the Figure 6 corresponds.

Wenn das zweite Markierungsteil 22 mit dem Riemen 4 durch das Referenzwechselfeld 26 bewegt wird, wird dies ebenfalls von dem Transmitter 12 erfasst. Denn der Transmitter 12 ist zur Erfassung des zweiten Reaktionswechselfelds und der zugehörigen zweiten Erfassungszeit T2 ausgebildet, wenn das zweite Markierungsteil 22 an dem Transmitter 12 vorbeigeführt wird.If the second marking part 22 with the belt 4 is moved through the reference alternating field 26, this is also detected by the transmitter 12. This is because the transmitter 12 is designed to detect the second alternating reaction field and the associated second detection time T2 when the second marking part 22 is guided past the transmitter 12.

Der Riemen 4 wird mit einer Riemengeschwindigkeit in Umfangsrichtung U von der Antriebsvorrichtung 6 angetrieben. Bei einer beispielhaft angenommen, konstanten Riemengeschwindigkeit des Riemens 4 vergrößert sich der zeitliche Abstand zwischen der ersten Erfassungszeit T1 und der zweiten Erfassungszeit T2, wenn sich die auf den Riemen 4 in Umfangsrichtung U wirkenden Zugkräfte vergrößern. Denn durch die Vergrößerung der Zugkräfte wird der Messabstand M zwischen dem zweiten Markierungsteil 22 und dem ersten Markierungsteil 20 vergrößert. Entsprechend dem vergrößerten Messabstand 11 vergrößert sich deshalb auch der zeitliche Abstand zwischen der zweiten Erfassungszeit T2 und der ersten Erfassungszeit T1.The belt 4 is driven by the drive device 6 at a belt speed in the circumferential direction U. If, for example, the belt speed of the belt 4 is assumed to be constant, the time interval between the first detection time T1 and the second detection time T2 increases when the speed on the belt 4 increases Increase the tensile forces acting in the circumferential direction U. By increasing the tensile forces, the measuring distance M between the second marking part 22 and the first marking part 20 is increased. Corresponding to the increased measuring distance 11, the time interval between the second detection time T2 and the first detection time T1 also increases.

Das System 2 ist außerdem dazu konfiguriert, die Riemengeschwindigkeit des Riemens 4 in Umfangsrichtung U basierend auf dem ersten Reaktionswechselfeld und/oder dem zweiten Reaktionswechselfeld zu ermitteln. Dazu kann der Transmitter 12 als ein magnetoresistiver Sensor ausgebildet sein oder diesen aufweisen. Somit ist der Transmitter 12 des Systems 2 dazu ausgebildet, die Riemengeschwindigkeit des Riemens 4 in Umfangsrichtung U basierend auf dem ersten Reaktionswechselfeld und/oder dem zweiten Reaktionswechselfeld zu ermitteln.The system 2 is also configured to determine the belt speed of the belt 4 in the circumferential direction U based on the first alternating reaction field and/or the second alternating reaction field. For this purpose, the transmitter 12 can be designed as or have a magnetoresistive sensor. Thus, the transmitter 12 of the system 2 is designed to determine the belt speed of the belt 4 in the circumferential direction U based on the first alternating reaction field and/or the second alternating reaction field.

Der Transmitter 12 ist mit der Auswerteeinheit 14, insbesondere über eine Signalleitung, gekoppelt. Dadurch stehen der Auswerteeinheit die von dem Transmitter 12 erfassten Messgrößen zur Verfügung. Die Auswerteeinheit 14 ist dazu konfiguriert, eine Längsdehnung des Riemens 4 basierend auf dem Referenzabstand R, der Riemengeschwindigkeit, der ersten Erfassungszeit T1 und der zweiten Erfassungszeit T2 zu ermitteln. Dazu kann die folgende Formel in der Auswerteeinheit 14 hinterlegt sein. Die Auswerteeinheit 14 kann zur Auswertung der Formel gebildet sein. L ä ngsdehnung = Riemengeschwindigkeit ∗ T 2 − T 1 R − 1

Figure imgb0001
The transmitter 12 is coupled to the evaluation unit 14, in particular via a signal line. This means that the measurement variables recorded by the transmitter 12 are available to the evaluation unit. The evaluation unit 14 is configured to determine a longitudinal elongation of the belt 4 based on the reference distance R, the belt speed, the first detection time T1 and the second detection time T2. For this purpose, the following formula can be stored in the evaluation unit 14. The evaluation unit 14 can be designed to evaluate the formula. L ä ngselongation = Belt speed ∗ T 2 − T 1 R − 1
Figure imgb0001

Wie es beispielhaft aus der Figur 1 zu entnehmen ist, ist es bevorzugt vorgesehen, dass der Transmitter 12 dem Zugtrum 52 zugewandt ist. Außerdem ist es bevorzugt vorgesehen, dass der Referenzabstand R zwischen dem zweiten Markierungsteil 22 und dem ersten Markierungsteil 20 kleiner ist als die Trumlänge B des Zugtrums 52. So ist es bevorzugt vorgesehen, dass der Referenzabstand R maximal 70 % oder maximal 50 % der Trumlänge W des Zugtrums 52 ist.As exemplified by the Figure 1 As can be seen, it is preferably provided that the transmitter 12 faces the tension strand 52. In addition, it is preferably provided that the reference distance R between the second marking part 22 and the first marking part 20 is smaller than the strand length B of the tension strand 52. It is therefore preferably provided that the reference distance R is a maximum of 70% or a maximum of 50% of the strand length W of the tension strand 52.

Aus der Figur 2 kann darüber hinaus exemplarisch entnommen werden, dass es bevorzugt ist, dass das erste Markierungsteil 20 einstückig ausgebildet ist und dass das zweite Markierungsteil 22 einstückig ausgebildet.From the Figure 2 It can also be seen as an example that it is preferred that the first marking part 20 is formed in one piece and that the second marking part 22 is formed in one piece.

Eine erfindungsgemäße Ausgestaltung der beiden Markierungsteile 20, 22 ist schematisch aus dem Abschnitt des Riemens 4 zu entnehmen, wie dieser beispielhaft in der Figur 7 schematisch dargestellt ist. Die stirnseitigen Enden der beiden Markierungsteile 20, 22 sind über Verbindungsstege 38, 40 derart mechanisch verbunden, dass die beiden Markierungsteile 20, 22 und die beiden Verbindungsstege 38, 40 nach Art eines Rahmens 42 angeordnet und/oder umlaufend angeordnet sind. Die beiden Verbindungsstege 38, 40 können elektrisch isolierend ausgebildet sein. Es ist jedoch auch möglich, dass die beiden Verbindungsstege 38, 40 stoffschlüssig und ununterbrochen mit den beiden Markierungsteilen 20, 22 ausgebildet sind. Mit anderen Worten ist es möglich, dass ein ferromagnetischer Rahmen 42 jedes der beiden Markierungsteile 20, 22 und jeden der beiden Verbindungsstege 38, 40 bildet. Der Rahmen 42 bzw. die Verbindungsstege 38, 40 bieten den Vorteil, dass der vorbestimmte Referenzabstand R zwischen den beiden Markierungsteilen 20, 22 in dem unbelasteten Zustand des Riemens 4 besonders einfach sichergestellt ist.An inventive design of the two marking parts 20, 22 can be seen schematically from the section of the belt 4, as shown by way of example in the Figure 7 schematic is shown. The front ends of the two marking parts 20, 22 are mechanically connected via connecting webs 38, 40 in such a way that the two marking parts 20, 22 and the two connecting webs 38, 40 are arranged in the manner of a frame 42 and/or are arranged circumferentially. The two connecting webs 38, 40 can be designed to be electrically insulating. However, it is also possible for the two connecting webs 38, 40 to be formed in a cohesive and uninterrupted manner with the two marking parts 20, 22. In other words, it is possible for a ferromagnetic frame 42 to form each of the two marking parts 20, 22 and each of the two connecting webs 38, 40. The frame 42 or the connecting webs 38, 40 offer the advantage that the predetermined reference distance R between the two marking parts 20, 22 is particularly easily ensured in the unloaded state of the belt 4.

Ergänzend sei darauf hingewiesen, dass "aufweisend" keine anderen Elemente oder Schritte ausschließt und "ein" oder "eine" keine Vielzahl ausschließt. Ferner sei darauf hingewiesen, dass Merkmale, die mit Verweis auf eines der obigen Ausführungsbeispiele beschrieben worden sind, auch in Kombination mit anderen Merkmalen anderer oben beschriebener Ausführungsbeispiele verwendet werden können. Bezugszeichen in den Ansprüchen sind nicht als Einschränkung anzusehen.In addition, it should be noted that "comprising" does not exclude other elements or steps and "a" or "an" does not exclude a plurality. Furthermore, it should be noted that features that have been described with reference to one of the above exemplary embodiments can also be used in combination with other features of other exemplary embodiments described above. Reference symbols in the claims are not to be viewed as a limitation.

Bezugszeichenliste (Teil der Beschreibung)List of reference symbols (part of the description)

AA
AbstandDistance
HH
mittlere Feldstärkemedium field strength
MM
MessabstandMeasuring distance
QQ
QuerrichtungTransverse direction
RR
ReferenzabstandReference distance
T1T1
erste Erfassungszeitfirst detection time
T2T2
zweite Erfassungszeitsecond acquisition time
UU
UmfangsrichtungCircumferential direction
WW
Trumlängespan length
22
Systemsystem
44
Riemenbelt
66
AntriebsvorrichtungDrive device
88th
Riemenscheibepulley
1010
Riemenscheibepulley
1212
TransmitterTransmitter
1414
AuswerteeinheitEvaluation unit
1616
BasismaterialBase material
1818
FestigkeitsträgerStrength members
2020
erste Markierungsteilfirst marking part
2222
zweites Markierungsteilsecond marking part
2424
CordCord
2626
ReferenzwechselfeldAlternating reference field
2828
erste Veränderung der Feldstärkefirst change in field strength
3030
zweite Veränderung der Feldstärkesecond change in field strength
3232
TrumDream
3434
erste Veränderung im Frequenzspektrumfirst change in the frequency spectrum
3636
zweite Veränderung im Frequenzspektrumsecond change in the frequency spectrum
3838
Verbindungsstegconnecting bridge
4040
Verbindungsstegconnecting bridge
4242
RahmenFrame
4444
AußenseiteOutside
4646
SeitenwandSide wall
4848
SeitenwandSide wall
5050
Vorrichtungcontraption
5252
Zugtrumpull section

Claims (11)

  1. System (2) for ascertaining a longitudinal extension of a belt (4), having:
    a belt (4),
    a drive device (6) with a plurality of belt pulleys (8, 10),
    a transmitter (12), and
    an evaluation unit (14) which can be designed in a manner combined with the transmitter (12),
    wherein the belt (4) has a base material (16), a reinforcement (18), a first ferromagnetic marking part (20) and a second ferromagnetic marking part (22),
    wherein the base material (16) is preferably composed of rubber material or polyurethane material,
    wherein the belt (4) is designed to revolve in a circumferential direction (U) in the form of a ring,
    wherein the belt (4) at least partially loops around the pulleys (8, 10) and can be driven in the circumferential direction (U) by the drive device (6),
    wherein the reinforcement (18) is embedded in the base material (16) as a continuous cord (24) helically wound in the circumferential direction (U),
    wherein the first marking part (20) and the second marking part (22) are each embedded in the base material (16) and/or are fastened to the base material (16),
    wherein the transmitter (12) is designed to generate a first, electromagnetic alternating field, which is referred to as the reference alternating field (26),
    wherein the first ferromagnetic marking part (20) is designed to change the reference alternating field (26) into a second, electromagnetic alternating field, which is referred to as the first reaction alternating field, when the reference alternating field (26) acts on the first ferromagnetic marking part (20),
    wherein the second ferromagnetic marking part (22) is designed to change the reference alternating field (26) into a third, electromagnetic alternating field, which is referred to as the second reaction alternating field, when the reference alternating field (26) acts on the second ferromagnetic marking part (22),
    wherein the second marking part (22) is arranged behind the first marking part (20) in the circumferential direction (U) with a predetermined reference spacing (R), at least in a non-loaded state of the belt (4),
    wherein the transmitter (12) is arranged without contact with the belt (4) in such a way that the first and the second marking part (22) can be guided past the transmitter (12) and can be guided through the reference alternating field (26) in succession by means of the belt (4), this resulting in the reference alternating field (26) acting on the first and the second marking part (20, 22) in succession,
    wherein the transmitter (12) is designed to detect the first reaction alternating field and an associated first detection time (T1) when the first marking part (20) is guided past the transmitter (12),
    wherein the transmitter (12) is designed to detect the second reaction alternating field and the associated second detection time (T2) when the second marking part (22) is guided past the transmitter (12),
    the system (2) is configured to ascertain a belt speed of the belt (2) in the circumferential direction (U) based on the first and/or the second reaction alternating field, and
    wherein the evaluation unit (14) is configured to ascertain a longitudinal extension of the belt (2) based on the reference spacing (R), the belt speed, the first detection time (T1) and the second detection time (T2),
    characterized in that
    the first and the second marking part (20, 22) are designed in a manner at least indirectly connected to each other by means of connecting webs (38, 40), so that the predetermined reference spacing (R) can be reliably ensured between the two marking parts in the circumferential direction in the non-loaded state of the belt.
  2. System (2) according to the preceding claim, characterized in that the evaluation unit (14) is configured to ascertain a remaining service life of the belt (4) based on a history of ascertained longitudinal extensions of the belt (4).
  3. System (2) according to either of the preceding claims, characterized in that the first detection time (T1) represents a time of a maximum change in the reference alternating field (26) through the first marking part (20), and in that the second detection time (T2) represents a time of a maximum change in the reference alternating field (26) through the second marking part (22).
  4. System (2) according to one of the preceding claims, characterized in that the transmitter (12), in particular as a part of a transmitter evaluation unit, is arranged without contact on a strand (32) of the belt (4).
  5. System (2) according to the preceding claim, characterized in that the transmitter (12), in particular as a part of the transmitter evaluation unit, is arranged with a spacing (A) of between 1 mm and 50 cm from the strand (32) of the belt (4).
  6. System (2) according to one of the preceding claims, characterized in that the reference spacing (R) is less than the minimum strand length (W) of the belt (4).
  7. System (2) according to one of the preceding claims, characterized in that the reference spacing (R) is at most 90%, 80%, 70%, 60% or 50% of the strand length (W).
  8. System (2) according to one of the preceding claims, characterized in that each marking part (20, 22) is of passive design.
  9. System (2) according to one of the preceding claims, characterized in that each marking part (20, 22) is designed as a rod-like and/or film-like marking part (20, 22), wherein each marking part (20, 22) extends transversely to the circumferential direction (U) with its greatest extent.
  10. System (2) according to one of the preceding claims, characterized in that each marking part (20, 22) is prefabricated.
  11. System (2) according to one of the preceding claims, characterized in that each marking part (20, 22) is of one-piece design.
EP19190163.6A 2018-09-12 2019-08-06 System for determining a longitudinal elongation of a belt Active EP3623748B1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE102018215478.3A DE102018215478A1 (en) 2018-09-12 2018-09-12 system

Publications (2)

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EP3623748A1 EP3623748A1 (en) 2020-03-18
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DE102021200478A1 (en) 2021-01-20 2022-07-21 Contitech Antriebssysteme Gmbh Device and method for determining longitudinal elongation of a belt
DE102021202803A1 (en) 2021-03-23 2022-09-29 Contitech Antriebssysteme Gmbh Device and method for determining a longitudinal elongation and an average speed of a belt, and for determining a speed of at least one pulley

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JPH082565Y2 (en) * 1992-03-31 1996-01-29 株式会社椿本チエイン Endless moving body elongation measuring device
DE59902745D1 (en) * 1998-02-13 2002-10-24 Phoenix Ag DEVICE FOR CONTINUOUSLY MONITORING A CONNECTION OF A CONVEYOR BELT
DE102010002551A1 (en) * 2010-03-03 2011-09-08 Arntz Beteiligungs Gmbh & Co. Kg A belt for transmitting a drive movement, a device for driving a belt and method for putting a belt into operation
DE102011051923A1 (en) * 2011-07-19 2013-01-24 Contitech Transportbandsysteme Gmbh Device for monitoring a conveyor system for detecting damage to a conveyor belt by means of sequential conductor loops and a sequential slot protection system
DE102013111191A1 (en) * 2013-10-10 2015-04-16 Contitech Transportbandsysteme Gmbh Method and system for non-contact monitoring of a conveyor belt for damage
CN104692078B (en) * 2015-02-03 2017-01-18 赵磊 Method for monitoring running state of belt-type conveyer
JP6701042B2 (en) * 2016-09-20 2020-05-27 株式会社ブリヂストン Conveyor belt elongation measuring device and conveyor belt elongation measuring method

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